Acquisitions Independence Bank Acquisition (Details) - USD ($) $ / shares in Units, $ in Thousands		9 Months Ended
	Jan. 26, 2015	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Acquisitions
Consideration paid		$ 118,900
Cash consideration		$ 766
Closing stock price of common stock		$ 20.32
Goodwill		$ 50,832	$ 22,950	$ 22,950
IDPK
Acquisitions
Consideration paid	$ 79,777
Cash consideration for common stockholders	6,100
Cash consideration for holders of stock options and warrants	1,500
Warrants assumed	$ 1,300
Number of shares of common stock issued as consideration	4,480,645
Value of shares of common stock issued as consideration	$ 70,900
Closing stock price of common stock	$ 15.83
Goodwill	$ 27,882