Derivative Instruments - Effect on Statement of Operations and Comprehensive Income (Detail) (USD $) In Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2011		Jun. 30, 2010		Jun. 30, 2011		Jun. 30, 2010
Effect of derivatives on statement of operations and comprehensive income [Line Items]
Effect of Derivatives On the Statement of Operations and Comprehensive Income, Amount of Income (Loss) Recognized in Income	$ (216,760)	[1]	$ (175,535)	[1]	$ (422,908)	[1]	$ (356,373)	[1]
Effect of Derivatives On the Statement of Operations and Comprehensive Income, Unrealized Gains (Losses) on Interest Rate Swaps	$ (466,943)		$ (593,038)		$ (297,635)		$ (709,770)

[1] Net interest payments on interest rate swaps is presented in the Company's consolidated statement of operations as realized gains (losses) on interest rate swaps.