Derivative Financial Instruments - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Net gain (loss) on derivative financial instruments	$ (99,689,000)	$ (82,837,000)
Net deferred losses expected to be reclassified from AOCI over next 12 months	(78,400,000)
Derivative contracts, maturity date	Dec. 31, 2017
Fair value of derivative contracts	58,500,000
EPCI projects [Member]
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Notional value of outstanding derivative contracts	424,800,000
Foreign Exchange Forward
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Notional value of outstanding derivative contracts	$ 631,400,000