Derivative Financial Instruments (Textuals) (Details)	6 Months Ended
Jun. 30, 2012
Derivative Financial Instruments (Textuals) [Abstract]
Percent of future hedged production with primary counterparties	85.00%
Percent hedged with largest counterparty	25.00%

Percentage of our future hedged production that is under contract with our primary and largest counterparties.

No definition available.

Name:	nfx_PercentOfFutureHedgedProductionWithPrimaryCounterparties
Namespace Prefix:	nfx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration