Derivative Financial Instruments - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Net gain (loss) on derivative financial instruments	$ (45,386,000)	$ 11,735,000
Net deferred gains expected to be reclassified from AOCI over next 12 months	18,200,000
Notional value of outstanding derivative contracts	1,100,000,000
Derivative contracts, maturity date	Oct. 31, 2017
Fair value of Derivative contracts	28,800,000
EPCI projects
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional value of outstanding derivative contracts	$ 660,400,000