Derivative Financial Instruments - Recognized in our Consolidated Balance Sheets and Consolidated Statements of Operations Related to our FOREX Contracts Designated as Cash Flow Hedges (Detail) (FOREX contracts [Member], Derivative designated as accounting hedges [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in AOCGL on derivative (effective portion)	$ 2,486	$ 1,720	$ (7,539)	$ 6,191
Contract drilling expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of loss reclassified from AOCGL into income (effective portion)	(5,572)	(2,873)	(2,951)	(5,300)
Foreign currency transaction gain (loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in income on derivative (ineffective portion and amount excluded from effectiveness testing)	$ 59		$ (59)	$ (39)