Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 17,341	$ 16,828	$ 35,163	$ 32,072
Other comprehensive income:
Change in unrealized net gain on available-for-sale securities	(5,208)	2,366	(4,715)	4,207
Change in value of interest rate cap	(4)	(195)	(10)	(153)
Comprehensive Income	$ 12,129	$ 18,999	$ 30,438	$ 36,126