0000001 - Document - Cover link:presentationLink link:calculationLink link:definitionLink 0000002 - Statement - Consolidated Balance Sheet Unaudited link:presentationLink link:calculationLink link:definitionLink 0000003 - Statement - Consolidated Balance Sheet Unaudited Parentheticals link:presentationLink link:calculationLink link:definitionLink 0000004 - Statement - Consolidated Statement of Income Unaudited link:presentationLink link:calculationLink link:definitionLink 0000005 - Statement - Consolidated Statement of Comprehensive Income Unaudited link:presentationLink link:calculationLink link:definitionLink 0000006 - Statement - Consolidated Statement of Comprehensive Income Unaudited Parentheticals link:presentationLink link:calculationLink link:definitionLink 0000007 - Statement - Consolidated Statement of Cash Flows link:presentationLink link:calculationLink link:definitionLink 0000008 - Statement - Consolidated Statement of Equity link:presentationLink link:calculationLink link:definitionLink 0000009 - Disclosure - Operations and Significant Accounting Policies link:presentationLink link:calculationLink link:definitionLink 0000010 - Disclosure - Regulatory Matters link:presentationLink link:calculationLink link:definitionLink 0000011 - Disclosure - Equity Investments link:presentationLink link:calculationLink link:definitionLink 0000012 - Disclosure - Fair Value link:presentationLink link:calculationLink link:definitionLink 0000013 - Disclosure - Short-Term and Long-Term Debt link:presentationLink link:calculationLink link:definitionLink 0000014 - Disclosure - Commitments, Guarantees and Contingencies link:presentationLink link:calculationLink link:definitionLink 0000015 - Disclosure - Earnings Per Share and Common Stock link:presentationLink link:calculationLink link:definitionLink 0000016 - Disclosure - Income Tax Expense link:presentationLink link:calculationLink link:definitionLink 0000017 - Disclosure - Pension and Other Postretirement Benefit Plans link:presentationLink link:calculationLink link:definitionLink 0000018 - Disclosure - Business Segments link:presentationLink link:calculationLink link:definitionLink 0000019 - Disclosure - Subsequent Event - Agreement and Plan of Merger link:presentationLink link:calculationLink link:definitionLink 9954471 - Disclosure - Operations and Significant Accounting Policies (Policies) link:presentationLink link:calculationLink link:definitionLink 9954472 - Disclosure - Operations and Significant Accounting Policies (Tables) link:presentationLink link:calculationLink link:definitionLink 9954473 - Disclosure - Regulatory Matters (Tables) link:presentationLink link:calculationLink link:definitionLink 9954474 - Disclosure - Equity Investments (Tables) link:presentationLink link:calculationLink link:definitionLink 9954475 - Disclosure - Fair Value (Tables) link:presentationLink link:calculationLink link:definitionLink 9954476 - Disclosure - Short-Term and Long-Term Debt (Tables) link:presentationLink link:calculationLink link:definitionLink 9954477 - Disclosure - Earnings Per Share and Common Stock (Tables) link:presentationLink link:calculationLink link:definitionLink 9954478 - Disclosure - Income Tax Expense (Tables) link:presentationLink link:calculationLink link:definitionLink 9954479 - Disclosure - Pension and Other Postretirement Benefit Plans (Tables) link:presentationLink link:calculationLink link:definitionLink 9954480 - Disclosure - Business Segments (Tables) link:presentationLink link:calculationLink link:definitionLink 9954481 - Disclosure - Operations and Significant Accounting Policies - Cash, Cash Equivalents and Restricted Cash (Details) link:presentationLink link:calculationLink link:definitionLink 9954482 - Disclosure - Operations and Significant Accounting Policies - Inventories (Details) link:presentationLink link:calculationLink link:definitionLink 9954483 - Disclosure - Operations and Significant Accounting Policies - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9954484 - Disclosure - Operations and Significant Accounting Policies - Other Non-Current Assets (Details) link:presentationLink link:calculationLink link:definitionLink 9954485 - Disclosure - Operations and Significant Accounting Policies - Other Current Liabilities (Details) link:presentationLink link:calculationLink link:definitionLink 9954486 - Disclosure - Operations and Significant Accounting Policies - Other Non-Current Liabilities (Details) link:presentationLink link:calculationLink link:definitionLink 9954487 - Disclosure - Operations and Significant Accounting Policies - Other Income (Details) link:presentationLink link:calculationLink link:definitionLink 9954488 - Disclosure - Operations and Significant Accounting Policies - Supplemental Statement of Cash Flows Information (Details) link:presentationLink link:calculationLink link:definitionLink 9954489 - Disclosure - Regulatory Matters - Electric Rates (Details) link:presentationLink link:calculationLink link:definitionLink 9954490 - Disclosure - Regulatory Matters - Regulatory Assets and Liabilities (Details) link:presentationLink link:calculationLink link:definitionLink 9954491 - Disclosure - Equity Investments - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9954492 - Disclosure - Equity Investments - Investment in ATC (Details) link:presentationLink link:calculationLink link:definitionLink 9954493 - Disclosure - Fair Value - Recurring Fair Value Measures (Details) link:presentationLink link:calculationLink link:definitionLink 9954494 - Disclosure - Fair Value - Fair Value of Financial Instruments and Assets Measured on a Nonrecurring Basis (Details) link:presentationLink link:calculationLink link:definitionLink 9954495 - Disclosure - Short-Term and Long-Term Debt - Schedule of Short-Term and Long-Term Debt (Details) link:presentationLink link:calculationLink link:definitionLink 9954495 - Disclosure - Short-Term and Long-Term Debt - Schedule of Short-Term and Long-Term Debt (Details) link:presentationLink link:calculationLink link:definitionLink 9954496 - Disclosure - Short-Term and Long-Term Debt - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9954497 - Disclosure - Commitments, Guarantees and Contingencies - Power Purchase Agreements (Details) link:presentationLink link:calculationLink link:definitionLink 9954498 - Disclosure - Commitments, Guarantees and Contingencies - Environmental Matters (Details) link:presentationLink link:calculationLink link:definitionLink 9954499 - Disclosure - Commitments, Guarantees and Contingencies - Other Matters (Details) link:presentationLink link:calculationLink link:definitionLink 9954500 - Disclosure - Earnings Per Share and Common Stock (Details) link:presentationLink link:calculationLink link:definitionLink 9954501 - Disclosure - Income Tax Expense - Schedule of Income Tax Expense (Details) link:presentationLink link:calculationLink link:definitionLink 9954502 - Disclosure - Income Tax Expense - Reconciliation of Taxes from Federal Statutory Rate to Total Income Tax Expense (Details) link:presentationLink link:calculationLink link:definitionLink 9954503 - Disclosure - Income Tax Expense - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9954504 - Disclosure - Pension and Other Postretirement Benefit Plans (Details) link:presentationLink link:calculationLink link:definitionLink 9954505 - Disclosure - Pension and Other Postretirement Benefit Plans - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9954506 - Disclosure - Business Segments - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9954507 - Disclosure - Business Segments - (Details) link:presentationLink link:calculationLink link:definitionLink 9954508 - Disclosure - Subsequent Event - Agreement and Plan of Merger - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink