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Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Millions | 3 Months Ended |
--- | --- | ---
Mar. 31, 2021 | Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | $ 697 | $ 675
Derivative liabilities | 386 | 478
CECONY |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 570 | 550
Netting Adjustment |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 44 | 53
Derivative liabilities | 37 | 46
Netting Adjustment | CECONY |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | (13) | (16)
Level 1 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 456 | 450
Derivative liabilities | 5 | 7
Level 1 | CECONY |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 434 | 426
Level 2 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 191 | 168
Derivative liabilities | 326 | 402
Level 2 | CECONY |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 148 | 140
Level 3 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 6 | 4
Derivative liabilities | 18 | 23
Level 3 | CECONY |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 1 | 0
Commodity |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 120 | 118
Derivative liabilities | 328 | 372
Transfer out of level 3 | 1 |
Commodity | CECONY |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 30 | 19
Derivative liabilities | 246 | 268
Commodity | Netting Adjustment |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 44 | 53
Derivative liabilities | 37 | 46
Commodity | Netting Adjustment | CECONY |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | (13) | (16)
Derivative liabilities | (14) | (19)
Commodity | Level 1 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 18 | 19
Derivative liabilities | 5 | 7
Commodity | Level 1 | CECONY |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 15 | 15
Derivative liabilities | 1 | 3
Commodity | Level 2 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 52 | 42
Derivative liabilities | 268 | 296
Commodity | Level 2 | CECONY |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 27 | 20
Derivative liabilities | 251 | 274
Commodity | Level 3 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 6 | 4
Derivative liabilities | 18 | 23
Commodity | Level 3 | CECONY |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 1 | 0
Derivative liabilities | 8 | 10
Interest rate swap |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 11 | 0
Derivative liabilities | 58 | 106
Interest rate swap | Netting Adjustment |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 0 | 0
Derivative liabilities | 0 | 0
Interest rate swap | Level 1 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 0 | 0
Derivative liabilities | 0 | 0
Interest rate swap | Level 2 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 11 | 0
Derivative liabilities | 58 | 106
Interest rate swap | Level 3 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 0 | 0
Derivative liabilities | 0 | 0
Other |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 566 | 557
Other | CECONY |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 540 | 531
Other | Netting Adjustment |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 0 | 0
Other | Netting Adjustment | CECONY |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 0 | 0
Other | Level 1 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 438 | 431
Other | Level 1 | CECONY |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 419 | 411
Other | Level 2 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 128 | 126
Other | Level 2 | CECONY |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 121 | 120
Other | Level 3 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 0 | 0
Other | Level 3 | CECONY |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | $ 0 | $ 0

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- Definition Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=121572278&loc=d3e13433-108611 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 + Details
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