Schedule of Location of Derivatives on Income Statement (Details) (Interest Rate Contract, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Interest Rate Contract
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Amount of gain (loss) recognized in OCI (effective portion)	$ 15,030	$ (141,392)	$ (273,389)
Amount of loss reclassified from OCI into net income as interest expense (effective portion)	(116,847)	(116,792)	(102,614)
Amount of loss recognized in net income as interest expense (ineffective portion)	$ (205)	$ (178)	$ (654)