Business Combinations - Focus Business Bank - Pro Forma Information (Details) - Focus Business Bank - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Pro Forma Information
Net interest income	$ 83,876	$ 68,175
Provision (credit) for loan losses	82	(38)
Non interest income	11,443	9,624
Noninterest expense	60,372	53,600
Income before income taxes	34,865	24,237
Income tax expense	13,941	8,784
Net income	$ 20,924	$ 15,453
Net income per share - basic (in dollars per share)	$ 0.56	$ 0.41
Net income per share - diluted (in dollars per share)	$ 0.55	$ 0.41