2102100 - Disclosure - Business Segments link:presentationLink link:calculationLink link:definitionLink 2402402 - Disclosure - Business Segments (Details) link:presentationLink link:calculationLink link:definitionLink 2302301 - Disclosure - Business Segments (Tables) link:presentationLink link:calculationLink link:definitionLink 2111100 - Disclosure - Commitments, Guarantees and Contingencies link:presentationLink link:calculationLink link:definitionLink 2411403 - Disclosure - Commitments, Guarantees and Contingencies - Coal Rail and Shipping Contracts (Details) link:presentationLink link:calculationLink link:definitionLink 2411406 - Disclosure - Commitments, Guarantees and Contingencies - Environmental Matters (Details) link:presentationLink link:calculationLink link:definitionLink 2411404 - Disclosure - Commitments, Guarantees and Contingencies - Leasing Agreements (Details) link:presentationLink link:calculationLink link:definitionLink 2411408 - Disclosure - Commitments, Guarantees and Contingencies - Legal Proceedings (Details) link:presentationLink link:calculationLink link:definitionLink 2411402 - Disclosure - Commitments, Guarantees and Contingencies - North Dakota Wind Development (Details) link:presentationLink link:calculationLink link:definitionLink 2411407 - Disclosure - Commitments, Guarantees and Contingencies - Other Matters (Details) link:presentationLink link:calculationLink link:definitionLink 2411401 - Disclosure - Commitments, Guarantees and Contingencies - Power Purchase Agreements (Details) link:presentationLink link:calculationLink link:definitionLink 2411405 - Disclosure - Commitments, Guarantees and Contingencies - Transmission (Details) link:presentationLink link:calculationLink link:definitionLink 2112100 - Disclosure - Common Stock and Earnings Per Share link:presentationLink link:calculationLink link:definitionLink 2412403 - Disclosure - Common Stock and Earnings Per Share - Reconciliation of Basic and Diluted Earnings Per Share (Details) link:presentationLink link:calculationLink link:definitionLink 2412402 - Disclosure - Common Stock and Earnings Per Share - Summary of Common Stock (Details) link:presentationLink link:calculationLink link:definitionLink 2312301 - Disclosure - Common Stock and Earnings Per Share (Tables) link:presentationLink link:calculationLink link:definitionLink 1002000 - Statement - Consilidated Statement of Income link:presentationLink link:calculationLink link:definitionLink 1001000 - Statement - Consolidated Balance Sheet link:presentationLink link:calculationLink link:definitionLink 1001501 - Statement - Consolidated Balance Sheet Parentheticals link:presentationLink link:calculationLink link:definitionLink 1004000 - Statement - Consolidated Statement of Cash Flows link:presentationLink link:calculationLink link:definitionLink 1003000 - Statement - Consolidated Statement of Comprehensive Income link:presentationLink link:calculationLink link:definitionLink 1003501 - Statement - Consolidated Statement of Comprehensive Income Parentheticals link:presentationLink link:calculationLink link:definitionLink 1005000 - Statement - Consolidated Statement of Shareholders' Equity link:presentationLink link:calculationLink link:definitionLink 2108100 - Disclosure - Derivatives link:presentationLink link:calculationLink link:definitionLink 2408402 - Disclosure - Derivatives (Details) link:presentationLink link:calculationLink link:definitionLink 2408401 - Disclosure - Derivatives - Hedged Items (Details) link:presentationLink link:calculationLink link:definitionLink 0001000 - Document - Document and Entity Information Document link:presentationLink link:calculationLink link:definitionLink 2117100 - Disclosure - Employee Stock and Incentive Plans link:presentationLink link:calculationLink link:definitionLink 2417402 - Disclosure - Employee Stock and Incentive Plans - Employee Stock Ownership Plan (Details) link:presentationLink link:calculationLink link:definitionLink 2417405 - Disclosure - Employee Stock and Incentive Plans - Non-Qualified Stock Options (Details) link:presentationLink link:calculationLink link:definitionLink 2417407 - Disclosure - Employee Stock and Incentive Plans - Performance Shares and Restricted Stock Units (Details) link:presentationLink link:calculationLink link:definitionLink 2417404 - Disclosure - Employee Stock and Incentive Plans - Share-Based Compensation Expense (Details) link:presentationLink link:calculationLink link:definitionLink 2417403 - Disclosure - Employee Stock and Incentive Plans - Stock-Based Compensation (Details) link:presentationLink link:calculationLink link:definitionLink 2417406 - Disclosure - Employee Stock and Incentive Plans - Stock Options, Range of Exercise Price (Details) link:presentationLink link:calculationLink link:definitionLink 2317301 - Disclosure - Employee Stock and Incentive Plans (Tables) link:presentationLink link:calculationLink link:definitionLink 2109100 - Disclosure - Fair Value link:presentationLink link:calculationLink link:definitionLink 2409404 - Disclosure - Fair Value - Financial Instruments (Details) link:presentationLink link:calculationLink link:definitionLink 2409403 - Disclosure - Fair Value - Recurring Fair Value Measures, Activity in Level 3 (Details) link:presentationLink link:calculationLink link:definitionLink 2409402 - Disclosure - Fair Value - Recurring Fair Value Measures (Details) link:presentationLink link:calculationLink link:definitionLink 2309301 - Disclosure - Fair Value (Tables) link:presentationLink link:calculationLink link:definitionLink 2114100 - Disclosure - Income Tax Expense link:presentationLink link:calculationLink link:definitionLink 2414404 - Disclosure - Income Tax Expense - Deferred Tax Assets and Liabilities (Details) link:presentationLink link:calculationLink link:definitionLink 2414402 - Disclosure - Income Tax Expense (Details) link:presentationLink link:calculationLink link:definitionLink 2414406 - Disclosure - Income Tax Expense - Gross Unrecognized Income Tax Benefits (Details) link:presentationLink link:calculationLink link:definitionLink 2414405 - Disclosure - Income Tax Expense - NOL and Tax Credit Carryforwards (Details) link:presentationLink link:calculationLink link:definitionLink 2414403 - Disclosure - Income Tax Expense - Reconciliation of Taxes from Federal Statutory Rate to Total Income Tax Expense (Details) link:presentationLink link:calculationLink link:definitionLink 2314301 - Disclosure - Income Tax Expense (Tables) link:presentationLink link:calculationLink link:definitionLink 2106100 - Disclosure - Investment in ATC link:presentationLink link:calculationLink link:definitionLink 2406402 - Disclosure - Investment in ATC (Details) link:presentationLink link:calculationLink link:definitionLink 2306301 - Disclosure - Investment in ATC (Tables) link:presentationLink link:calculationLink link:definitionLink 2107100 - Disclosure - Investments link:presentationLink link:calculationLink link:definitionLink 2407402 - Disclosure - Investments (Details) link:presentationLink link:calculationLink link:definitionLink 2407403 - Disclosure - Investments Parenthetical (Details) link:presentationLink link:calculationLink link:definitionLink 2307301 - Disclosure - Investments (Tables) link:presentationLink link:calculationLink link:definitionLink 2104100 - Disclosure - Jointly-Owned Facilities link:presentationLink link:calculationLink link:definitionLink 2404402 - Disclosure - Jointly-Owned Facilities (Details) link:presentationLink link:calculationLink link:definitionLink 2304301 - Disclosure - Jointly-Owned Facilities (Tables) link:presentationLink link:calculationLink link:definitionLink 2101100 - Disclosure - Operations and Significant Accounting Policies link:presentationLink link:calculationLink link:definitionLink 2401407 - Disclosure - Operations and Significant Accounting Policies - Concentraion of Credit Risk (Details) link:presentationLink link:calculationLink link:definitionLink 2401403 - Disclosure - Operations and Significant Accounting Policies (Details) link:presentationLink link:calculationLink link:definitionLink 2401403 - Disclosure - Operations and Significant Accounting Policies (Details) link:presentationLink link:calculationLink link:definitionLink 2401406 - Disclosure - Operations and Significant Accounting Policies - Investments and Other (Details) link:presentationLink link:calculationLink link:definitionLink 2401404 - Disclosure - Operations and Significant Accounting Policies - Minnesota Land Acres (Details) link:presentationLink link:calculationLink link:definitionLink 2201201 - Disclosure - Operations and Significant Accounting Policies (Policies) link:presentationLink link:calculationLink link:definitionLink 2401405 - Disclosure - Operations and Significant Accounting Policies - Supplemental Statement of Cash Flow Information (Details) link:presentationLink link:calculationLink link:definitionLink 2301302 - Disclosure - Operations and Significant Accounting Policies (Tables) link:presentationLink link:calculationLink link:definitionLink 2113100 - Disclosure - Other Income (Expense) link:presentationLink link:calculationLink link:definitionLink 2413402 - Disclosure - Other Income (Expense) (Details) link:presentationLink link:calculationLink link:definitionLink 2313301 - Disclosure - Other Income (Expense) (Tables) link:presentationLink link:calculationLink link:definitionLink 2116100 - Disclosure - Pension and Other Postretirement Benefit Plans link:presentationLink link:calculationLink link:definitionLink 2416405 - Disclosure - Pension and Other Postretirement Benefit Plans - Components of Net Periodic Benefit Expense (Details) link:presentationLink link:calculationLink link:definitionLink 2416402 - Disclosure - Pension and Other Postretirement Benefit Plans - Contributions (Details) link:presentationLink link:calculationLink link:definitionLink 2416409 - Disclosure - Pension and Other Postretirement Benefit Plans - Costs Recorded in Other Long-Term Assets and AOCI Expected to be Recognized as a Component of Net Pension and Postretirement Benefit Costs in the Next Fiscal Year (Details) link:presentationLink link:calculationLink link:definitionLink 2416408 - Disclosure - Pension and Other Postretirement Benefit Plans - Estimated Future Benefit Payments (Details) link:presentationLink link:calculationLink link:definitionLink 2416407 - Disclosure - Pension and Other Postretirement Benefit Plans - Information for Pension Plans with an Accumulated Benefit Obligation in Excess of Plan Assets (Details) link:presentationLink link:calculationLink link:definitionLink 2416403 - Disclosure - Pension and Other Postretirement Benefit Plans - Obligation and Funded Status (Details) link:presentationLink link:calculationLink link:definitionLink 2416406 - Disclosure - Pension and Other Postretirement Benefit Plans - Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income and Regulatory Assets (Details) link:presentationLink link:calculationLink link:definitionLink 2416412 - Disclosure - Pension and Other Postretirement Benefit Plans - Plan Asset Allocations (Details) link:presentationLink link:calculationLink link:definitionLink 2416414 - Disclosure - Pension and Other Postretirement Benefit Plans - Recurring Fair Value Measures, Activity in Level 3 (Details) link:presentationLink link:calculationLink link:definitionLink 2416413 - Disclosure - Pension and Other Postretirement Benefit Plans - Recurring Fair Value Measures (Details) link:presentationLink link:calculationLink link:definitionLink 2416411 - Disclosure - Pension and Other Postretirement Benefit Plans - Sensitivity of a One-Percentage-Point Change in Health Care Trend Rates (Details) link:presentationLink link:calculationLink link:definitionLink 2316301 - Disclosure - Pension and Other Postretirement Benefit Plans (Tables) link:presentationLink link:calculationLink link:definitionLink 2416404 - Disclosure - Pension and Other Postretirement Benefit Plans - Unrecognized Costs (Details) link:presentationLink link:calculationLink link:definitionLink 2416410 - Disclosure - Pension and Other Postretirement Benefit Plans - Weighted-Average Assumptions Used to Determine Benefit Obligation and Net Periodic Benefit Costs (Details) link:presentationLink link:calculationLink link:definitionLink 2103100 - Disclosure - Property, Plant and Equipment link:presentationLink link:calculationLink link:definitionLink 2403402 - Disclosure - Property, Plant and Equipment (Details) link:presentationLink link:calculationLink link:definitionLink 2303301 - Disclosure - Property, Plant and Equipment (Tables) link:presentationLink link:calculationLink link:definitionLink 2118100 - Disclosure - Quarterly Financial Data (Unaudited) link:presentationLink link:calculationLink link:definitionLink 2418402 - Disclosure - Quarterly Financial Data (Unaudited) (Details) link:presentationLink link:calculationLink link:definitionLink 2318301 - Disclosure - Quarterly Financial Data (Unaudited) (Tables) link:presentationLink link:calculationLink link:definitionLink 2105100 - Disclosure - Regulatory Matters link:presentationLink link:calculationLink link:definitionLink 2405403 - Disclosure - Regulatory Matters - Boswell Mercury Emission Reduction Plan (Details) link:presentationLink link:calculationLink link:definitionLink 2405402 - Disclosure - Regulatory Matters - Electric Rates (Details) link:presentationLink link:calculationLink link:definitionLink 2405404 - Disclosure - Regulatory Matters - The Patient Protection and Affordable Care Act of 2010 (PPACA) (Details) link:presentationLink link:calculationLink link:definitionLink 2405405 - Disclosure - Regulatory Matters - Regulatory Assets and Liabilities (Details) link:presentationLink link:calculationLink link:definitionLink 2305301 - Disclosure - Regulatory Matters (Tables) link:presentationLink link:calculationLink link:definitionLink 2119100 - Schedule - Schedule II link:presentationLink link:calculationLink link:definitionLink 2419401 - Schedule - Schedule II (Details) link:presentationLink link:calculationLink link:definitionLink 2110100 - Disclosure - Short-term and Long-term Debt link:presentationLink link:calculationLink link:definitionLink 2410402 - Disclosure - Short-Term and Long-Term Debt (Details) link:presentationLink link:calculationLink link:definitionLink 2410403 - Disclosure - Short-term and Long-term Debt - Schedule of Long-Term Debt (Details) link:presentationLink link:calculationLink link:definitionLink 2310301 - Disclosure - Short-Term and Long-Term Debt (Tables) link:presentationLink link:calculationLink link:definitionLink