Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 21,767	$ 17,341	$ 43,786	$ 35,163
Other comprehensive income:
Change in unrealized net gain on available-for-sale securities	3,292	(5,208)	2,515	(4,715)
Change in value of interest rate cap	27	(4)	43	(10)
Comprehensive income	$ 25,086	$ 12,129	$ 46,344	$ 30,438