Derivative Financial Instruments - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Derivative [Line Items]
Net gain (loss) on derivative financial instruments	$ (64,277,000)	$ (82,837,000)
Net deferred losses expected to be reclassified from AOCI over next 12 months	42,000,000
Notional value of outstanding derivative contracts	$ 643,000,000
Derivative contracts, maturity date	Dec. 31, 2017
Fair value of derivative contracts	$ 29,000,000
EPCI projects [Member]
Derivative [Line Items]
Notional value of outstanding derivative contracts	$ 381,000,000