Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
FHLB advances	$ 591,250	$ 806,500
Class A Common Stock
Common stock, par value (usd per share)	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	40,233,817	39,103,945
Common stock, shares outstanding	37,638,893	37,126,571
Treasury stock, shares	2,594,924	1,977,374
Class B Non-voting Common Stock
Common stock, par value (usd per share)	$ 0.001	$ 0.001
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	3,091,152	3,926,014
Common stock, shares outstanding	2,899,020	3,733,882
Treasury stock, shares	192,132	192,132