Business Combinations - Focus Business Bank - Estimated Fair Values of the Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Aug. 20, 2015	Mar. 31, 2015
Assets acquired:
Goodwill	$ 45,664	$ 45,664		$ 13,054
Focus Business Bank
Assets acquired:
Cash and cash item			$ 5,651
Federal funds sold and deposits in other financial institutions			168,415
Securities available-for-sale			53,940
Securities held-to-maturity			8,665
Loans held-for-sale			4,416
Net loans			170,353
Goodwill			32,620
Core deposit intangible asset			6,285
Corporate owned life insurance			7,067
Other assets, net			20,250
Total assets acquired			477,662
Liabilities assumed:
Deposits			405,123
Other liabilities			5,981
Total liabilities			411,104
Net assets acquired			$ 66,558