Derivative Financial Instruments (Details) (FOREX contracts [Member], USD $) In Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Derivative designated as accounting hedges [Member]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income, Effective Portion, Net
Amount of gain (loss) recognized in AOCGL on derivative (effective portion)	$ (17,263)	$ 5,550	$ (5,443)	$ 535
Derivative designated as accounting hedges [Member] | Contract drilling expense [Member]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net
Amount of gain (loss) recognized in AOCGL on derivative (effective portion)	4,792	178	12,407	1,300
Derivative designated as accounting hedges [Member] | Foreign currency transaction gain (loss) [Member]
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net
Amount of Gain Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing)
Designated as Hedging Instrument [Member] | Contract drilling expense [Member]
Derivative Instruments, Gain Recognized in Income, Net
Amount of Gain Recognized in Income	$ 2,362	$ 1,467	$ 9,593	$ 1,924