XML 58 R42.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Accounting for Derivative Instruments and Hedging Activities (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract] |
Net Notional Volume Buy/(sell) of NRG's Open Derivative Transactions Broken Out By Commodity | The following table summarizes the net notional volume buy/(sell) of NRG's open derivative transactions broken out by commodity, excluding those derivatives that qualified for the NPNS exception as of December 31, 2018 and 2017. Option contracts are reflected using delta volume. Delta volume equals the notional volume of an option adjusted for the probability that the option will be in-the-money at its expiration date.
|  | Total Volume
Commodity | Units | December 31, 2018 |  | December 31, 2017
|  | (In millions)
Emissions | Short Ton | (2 | ) |  | 1 |
Renewables Energy Certificates | Certificates | 1 |  |  | — |
Coal | Short Ton | 13 |  |  | 21 |
Natural Gas | MMBtu | (330 | ) |  | (20 | )
Oil | Barrels | 1 |  |  | — |
Power | MWh | 1 |  |  | 23 |
Capacity | MW/Day | (1 | ) |  | (1 | )
Interest | Dollars | $ | 1,000 |  |  | $ | 1,060 |
Equity | Shares | — |  |  | 1 |
Fair Value Within the Derivative Instrument Valuation On the Balance Sheet | The following table summarizes the fair value within the derivative instrument valuation on the balance sheet:
| Fair Value
| Derivative Assets |  | Derivative Liabilities
(In millions) | December 31, 2018 |  | December 31, 2017 |  | December 31, 2018 |  | December 31, 2017
Derivatives Not Designated as Cash Flow or Fair Value Hedges: |  |  |  |  |  |  |
Interest rate contracts current | $ | 17 |  |  | $ | 8 |  |  | $ | — |  |  | $ | 1 |
Interest rate contracts long-term | 22 |  |  | 31 |  |  | — |  |  | 5 |
Commodity contracts current | 747 |  |  | 616 |  |  | 673 |  |  | 536 |
Commodity contracts long-term | 295 |  |  | 128 |  |  | 304 |  |  | 138 |
Total Derivatives Not Designated as Cash Flow or Fair Value Hedges | $ | 1,081 |  |  | $ | 783 |  |  | $ | 977 |  |  | $ | 680 |
Offsetting of Derivatives by Counterparty Master Agreement Level and Collateral Received Or Paid | The following table summarizes the offsetting derivatives by counterparty master agreement level and collateral received or paid:
| Gross Amounts Not Offset in the Statement of Financial Position
| Gross Amounts of Recognized Assets/Liabilities |  | Derivative Instruments |  | Cash Collateral (Held)/Posted |  | Net Amount
As of December 31, 2018 | (In millions)
Commodity contracts: |  |  |  |  |  |  |
Derivative assets | $ | 1,042 |  |  | $ | (778 | ) |  | $ | (31 | ) |  | $ | 233 |
Derivative liabilities | (977 | ) |  | 778 |  |  | 114 |  |  | (85 | )
Total commodity contracts | 65 |  |  | — |  |  | 83 |  |  | 148 |
Interest rate contracts: |  |  |  |  |  |  |
Derivative assets | 39 |  |  | — |  |  | — |  |  | 39 |
Total interest rate contracts | 39 |  |  | — |  |  | — |  |  | 39 |
Total derivative instruments | $ | 104 |  |  | $ | — |  |  | $ | 83 |  |  | $ | 187 |
| Gross Amounts Not Offset in the Statement of Financial Position
| Gross Amounts of Recognized Assets/Liabilities |  | Derivative Instruments |  | Cash Collateral (Held)/Posted |  | Net Amount
As of December 31, 2017 | (In millions)
Commodity contracts: |  |  |  |  |  |  |
Derivative assets | $ | 744 |  |  | $ | (578 | ) |  | $ | (11 | ) |  | $ | 155 |
Derivative liabilities | (674 | ) |  | 578 |  |  | 72 |  |  | (24 | )
Total commodity contracts | 70 |  |  | — |  |  | 61 |  |  | 131 |
Interest rate contracts: |  |  |  |  |  |  |
Derivative assets | 39 |  |  | — |  |  | — |  |  | 39 |
Derivative liabilities | (6 | ) |  | — |  |  | — |  |  | (6 | )
Total interest rate contracts | 33 |  |  | — |  |  | — |  |  | 33 |
Total derivative instruments | $ | 103 |  |  | $ | — |  |  | $ | 61 |  |  | $ | 164 |
Effects on the Company's Accumulated OCI Balance Attributable to Cash Flow Hedge Derivatives, Net of Tax | The following table summarizes the effects on NRG's accumulated OCI balance attributable to cash flow hedge derivatives, net of tax:
| Interest Rate Contracts
| 2018 |  | 2017 |  | 2016
| (In millions)
Accumulated OCI beginning balance | $ | (54 | ) |  | $ | (66 | ) |  | $ | (101 | )
Reclassified from accumulated OCI to income: |  |  |  |  |
Due to realization of previously deferred amounts | 8 |  |  | 12 |  |  | 21 |
Mark-to-market of cash flow hedge accounting contracts | 21 |  |  | — |  |  | 14 |
Sale of NRG Yield and Renewables | $ | 25 |  |  | $ | — |  |  | $ | — |
Accumulated OCI ending balance, net of $0, $8 and $16 tax | $ | — |  |  | $ | (54 | ) |  | $ | (66 | )
Pre-tax Effects of Economic Hedges That Have Not Been Designated As Cash Flow Hedges, Ineffectiveness On Cash Flow Hedges And Trading Activity on the Company's Statement of Operations | The following table summarizes the pre-tax effects of economic hedges that have not been designated as cash flow hedges, and trading activity on the Company's statement of operations. The effect of commodity hedges is included within operating revenues and cost of operations and the effect of interest rate hedges is included in interest expense.
| Year Ended December 31,
| 2018 |  | 2017 |  | 2016
| (In millions)
Unrealized mark-to-market results |  |  |  |  |
Reversal of previously recognized unrealized (gains)/losses on settled positions related to economic hedges | $ | (73 | ) |  | $ | 47 |  |  | $ | (128 | )
Reversal of acquired gain positions related to economic hedges | (10 | ) |  | — |  |  | (12 | )
Net unrealized gains on open positions related to economic hedges | 97 |  |  | 159 |  |  | 12 |
Total unrealized mark-to-market gains/(losses) for economic hedging activities | 14 |  |  | 206 |  |  | (128 | )
Reversal of previously recognized unrealized (gains)/losses on settled positions related to trading activity | (12 | ) |  | (25 | ) |  | 10 |
Net unrealized gains on open positions related to trading activity | 29 |  |  | 14 |  |  | 18 |
Total unrealized mark-to-market gains/(losses) for trading activity | 17 |  |  | (11 | ) |  | 28 |
Total unrealized gains/(losses) | $ | 31 |  |  | $ | 195 |  |  | $ | (100 | )
| Year Ended December 31,
| 2018 |  | 2017 |  | 2016
| (In millions)
Unrealized (losses)/gains included in operating revenues | $ | (113 | ) |  | $ | 241 |  |  | $ | (608 | )
Unrealized gains/(losses) included in cost of operations | 144 |  |  | (46 | ) |  | 508 |
Total impact to statement of operations — energy commodities | $ | 31 |  |  | $ | 195 |  |  | $ | (100 | )
Total impact to statement of operations — interest rate contracts | $ | — |  |  | $ | 4 |  |  | $ | (8 | )

X
- Definition Schedule of Offsetting Assets and Liabilities [Table Text Block] + References No definition available. + Details
Name: | nrg_ScheduleOfOffsettingAssetsAndLiabilitiesTableTextBlock
Namespace Prefix: | nrg_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of gain (loss) on derivative and nonderivative instruments designated and qualifying as cash flow hedge recorded in accumulated other comprehensive income (AOCI) and reclassified into earnings. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959 + Details
Name: | us-gaap_ScheduleOfCashFlowHedgesIncludedInAccumulatedOtherComprehensiveIncomeLossTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of derivative instruments (including nonderivative instruments that are designated and qualify as hedging instruments) of (a) the location and amount of gains and losses reported in the statement of financial performance and (b) the location and fair value amounts of the instruments reported in the statement of financial position. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5618551-113959 + Details
Name: | us-gaap_ScheduleOfDerivativesInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the notional amounts of outstanding derivative positions. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5579245-113959 + Details
Name: | us-gaap_ScheduleOfNotionalAmountsOfOutstandingDerivativePositionsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of derivative instrument not designated or qualifying as hedging instrument. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4CC -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL109998890-113959 + Details
Name: | us-gaap_ScheduleOfOtherDerivativesNotDesignatedAsHedgingInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration