Effect of Derivative Instruments Qualifying and Designated as Hedging Instruments and Related Hedged Items in Fair Value Hedges on Consolidated Statement of Comprehensive Income (Detail) (Fair Value Hedging, USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivative	$ 439	$ 21,389
Amount of Gain (Loss) Recognized in Income on Hedged Item	10,974	(10,179)
Interest rate swaps | Interest expense, net of interest capitalized
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivative	4,982	4,437
Amount of Gain (Loss) Recognized in Income on Hedged Item	7,260	7,623
Interest rate swaps | Other income (expense)
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivative	(4,543)	(5,959)
Amount of Gain (Loss) Recognized in Income on Hedged Item	3,714	5,890
Foreign currency forward contracts | Other income (expense)
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivative		22,911
Amount of Gain (Loss) Recognized in Income on Hedged Item		$ (23,692)