Accumulated Other Comprehensive Loss - Summary of Changes in Accumulated Other Comprehensive Loss (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance	$ (2,853)	$ (9,164)
Other comprehensive income (loss) before reclassifications	412	(1,454)
Amounts reclassified out of accumulated other comprehensive income (loss)	1,676	2,832
Ending balance	(765)	(7,786)
Unrealized gains (losses) on cash flow hedges
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance	(2,853)	(12,416)
Other comprehensive income (loss) before reclassifications	412	(319)
Amounts reclassified out of accumulated other comprehensive income (loss)	1,676	3,153
Ending balance	(765)	(9,582)
Unrealized gains (losses) on investments available for sale
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance		3,252
Other comprehensive income (loss) before reclassifications		(1,135)
Amounts reclassified out of accumulated other comprehensive income (loss)		(321)
Ending balance		$ 1,796