v3.3.1.900

Derivative Instruments (Detail 5) (Details) - USD ($) $ in Millions | Dec. 31, 2015 | Dec. 31, 2014
--- | --- | ---
Derivative [Line Items] |  |  |
Derivative Asset, Fair Value, Gross Asset |  | $ 2,011 | $ 2,497
Derivative Asset, Not Offset, Policy Election Deduction |  | (1,804) | (2,087)
Derivative, Collateral, Obligation to Return Cash | [1] | (137) | (269)
Derivative Asset, Fair Value, Amount Offset Against Collateral |  | 70 | 141
Derivative Liability, Fair Value, Gross Liability |  | (2,207) | (2,226)
Derivative Liability, Not Offset, Policy Election Deduction |  | 1,804 | 2,087
Derivative, Collateral, Right to Reclaim Cash | [1] | 5 | 15
Derivative Liability, Fair Value, Amount Offset Against Collateral |  | (398) | (124)
Net derivative assets (liabilities) |  | (196) | 271
Derivative Fair Value, Amount Not Offset Against Collateral, Net |  | 0 | 0
Derivative, Collateral, Right to Reclaim Cash, Net | [1] | (132) | (254)
Derivative, Fair Value, Amount Offset Against Collateral, Net |  | (328) | 17
Commodity Exchange Traded Futures and Swaps Contracts [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative Asset, Fair Value, Gross Asset |  | 1,736 | 2,134
Derivative Asset, Not Offset, Policy Election Deduction |  | (1,602) | (1,865)
Derivative, Collateral, Obligation to Return Cash | [1] | (134) | (269)
Derivative Asset, Fair Value, Amount Offset Against Collateral |  | 0 | 0
Derivative Liability, Fair Value, Gross Liability |  | (1,604) | (1,870)
Derivative Liability, Not Offset, Policy Election Deduction |  | 1,602 | 1,865
Derivative, Collateral, Right to Reclaim Cash | [1] | 2 | 5
Derivative Liability, Fair Value, Amount Offset Against Collateral |  | 0 | 0
Commodity Forward Contract [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative Asset, Fair Value, Gross Asset |  | 274 | 359
Derivative Asset, Not Offset, Policy Election Deduction |  | (202) | (222)
Derivative, Collateral, Obligation to Return Cash | [1] | (3) | 0
Derivative Asset, Fair Value, Amount Offset Against Collateral |  | 69 | 137
Derivative Liability, Fair Value, Gross Liability |  | (513) | (242)
Derivative Liability, Not Offset, Policy Election Deduction |  | 202 | 222
Derivative, Collateral, Right to Reclaim Cash | [1] | 3 | 10
Derivative Liability, Fair Value, Amount Offset Against Collateral |  | (308) | (10)
Interest Rate Swap [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative Asset, Fair Value, Gross Asset |  | 1 | 4
Derivative Asset, Not Offset, Policy Election Deduction |  | 0 | 0
Derivative, Collateral, Obligation to Return Cash | [1] | 0 | 0
Derivative Asset, Fair Value, Amount Offset Against Collateral |  | 1 | 4
Derivative Liability, Fair Value, Gross Liability |  | (90) | (114)
Derivative Liability, Not Offset, Policy Election Deduction |  | 0 | 0
Derivative, Collateral, Right to Reclaim Cash | [1] | 0 | 0
Derivative Liability, Fair Value, Amount Offset Against Collateral |  | (90) | (114)
Net derivative assets (liabilities) |  | $ (89) | $ (110)
[1] | Negative balances represent margin deposits posted with us by our counterparties related to our derivative activities that are subject to a master netting arrangement. Positive balances reflect margin deposits and natural gas and power prepayments posted by us with our counterparties related to our derivative activities that are subject to a master netting arrangement. See Note 9 for a further discussion of our collateral.

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