CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (UNAUDITED) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Comprehensive income (loss)
Net income	$ 38,391	$ 34,918
Amounts related to available-for-sale securities:
Change in net unrealized gains	16,693	(7,705)
Amounts related to cash flow hedges:
Change in net unrealized losses	(12,656)	2,479
Reclassification adjustment for amounts included in net income	4,722	5,434
Other comprehensive income	8,759	208
Comprehensive income	$ 47,150	$ 35,126