Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement of Comprehensive Income [Abstract]
Net income	$ 43,050	$ 14,351	$ 79,072	$ 49,628
Other comprehensive income (loss):
Change in unrealized gains on securities	(627)	(1,336)	693	567
Less: reclassification adjustment for gains in net income	0	0	0	(30)
Decrease in fair value of cash flow hedge	(384)	(436)	722	(1,343)
Total other comprehensive income (loss)	(1,011)	(1,772)	1,415	(806)
Comprehensive income	42,039	12,579	80,487	48,822
Less: comprehensive income attributable to noncontrolling interest	(306)	0	(664)	0
Comprehensive income attributable to common stockholders	$ 41,733	$ 12,579	$ 79,823	$ 48,822