0000001 - Document - Cover link:presentationLink link:calculationLink link:definitionLink 9952151 - Statement - CONSOLIDATED BALANCE SHEET Unaudited link:presentationLink link:calculationLink link:definitionLink 9952152 - Statement - CONSOLIDATED BALANCE SHEET Unaudited (Parentheticals) link:presentationLink link:calculationLink link:definitionLink 9952153 - Statement - CONSOLIDATED STATEMENT OF INCOME Unaudited link:presentationLink link:calculationLink link:definitionLink 9952154 - Statement - CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME Unaudited link:presentationLink link:calculationLink link:definitionLink 9952155 - Statement - CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME Unaudited (Parentheticals) link:presentationLink link:calculationLink link:definitionLink 9952156 - Statement - CONSOLIDATED STATEMENT OF CASH FLOWS Unaudited link:presentationLink link:calculationLink link:definitionLink 9952157 - Statement - CONSOLIDATED STATEMENT OF EQUITY Unaudited link:presentationLink link:calculationLink link:definitionLink 9952158 - Disclosure - OPERATIONS AND SIGNIFICANT ACCOUNTING POLICIES link:presentationLink link:calculationLink link:definitionLink 9952159 - Disclosure - REGULATORY MATTERS link:presentationLink link:calculationLink link:definitionLink 9952160 - Disclosure - EQUITY INVESTMENTS link:presentationLink link:calculationLink link:definitionLink 9952161 - Disclosure - FAIR VALUE link:presentationLink link:calculationLink link:definitionLink 9952162 - Disclosure - SHORT-TERM AND LONG-TERM DEBT link:presentationLink link:calculationLink link:definitionLink 9952163 - Disclosure - COMMITMENTS, GUARANTEES AND CONTINGENCIES link:presentationLink link:calculationLink link:definitionLink 9952164 - Disclosure - EARNINGS PER SHARE AND COMMON STOCK link:presentationLink link:calculationLink link:definitionLink 9952165 - Disclosure - INCOME TAX EXPENSE link:presentationLink link:calculationLink link:definitionLink 9952166 - Disclosure - PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS link:presentationLink link:calculationLink link:definitionLink 9952167 - Disclosure - BUSINESS SEGMENTS link:presentationLink link:calculationLink link:definitionLink 9952168 - Disclosure - 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 (Expense) (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 - Components of Net Periodic Benefit Cost (Credit) (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 - Business Segments (Details) link:presentationLink link:calculationLink link:definitionLink 9954508 - Disclosure - AGREEMENT AND PLAN OF MERGER (Details) link:presentationLink link:calculationLink link:definitionLink