XML 70 R41.htm IDEA: XBRL DOCUMENT

Derivative Instruments - Additional Information (Detail) (Not Designated as Hedging Instrument [Member], USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2015 Mcf	Dec. 31, 2014 Mcf
Derivative [Line Items]
Gross derivative liability	1,656	1,455
Aggregate fair value of derivative instruments with credit-risk-related contingent features for which a net liability position existed (net of collateral)	1,200	97
Permitted to Offset Gross Derivative Asset with Financial Institutions [Member]
Derivative [Line Items]
Gross derivative liability	237	289
Natural Gas [Member] \| Commodity [Member]
Derivative [Line Items]
Financial derivative transactions	3,000,000	6,000,000

Fair value, before effects of master netting arrangements, of a financial liability or 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 liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

+ References+ Details