Schedule of Location of Derivatives on Income Statement (Details) (Interest Rate Contract, USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Interest Rate Contract
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Amount of gain (loss) recognized in OCI (effective portion)		$ 57,294		$ 51,385
Amount of loss reclassified from OCI into net income as interest expense (effective portion)	(22,923)	(30,585)	(47,607)	(60,515)
Amount of gain (loss) recognized in net income as interest expense (ineffective portion)		$ 212		$ 96