Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 21,036	$ 18,172	$ 64,822	$ 53,335
Other comprehensive income:
Change in unrealized net gain on available-for-sale securities	(2,419)	1,188	96	(3,527)
Change in value of interest rate cap	37	2	80	(8)
Comprehensive income	$ 18,654	$ 19,362	$ 64,998	$ 49,800