Acquisitions - Security California Bancorp - Narrative (Details) $ / shares in Units, $ in Thousands		3 Months Ended
	Jan. 31, 2016 USD ($) bank shares	Jun. 30, 2016 USD ($)	Jan. 29, 2016 USD ($) $ / shares	Dec. 31, 2015 USD ($)	Jun. 30, 2015 USD ($)
Business Acquisition [Line Items]
Assets		$ 3,598,653		$ 2,790,646
Loans		2,927,554		2,262,683	$ 2,118,323
Deposits		2,931,001		2,195,123
Closing stock price of common stock ($ per share) | $ / shares			$ 20.53
Goodwill		101,939		$ 50,832
Adjustment		$ 146
Security California Bancorp
Business Acquisition [Line Items]
Assets	$ 715,000
Loans	456,000
Deposits	$ 637,000
Equity issued (shares)	0.9629
Consideration paid	$ 120,174
Cash consideration	$ 788
Number Of branches | bank	6
Goodwill	$ 51,106
Common Stock | Security California Bancorp
Business Acquisition [Line Items]
Number of shares of common stock issued as consideration | shares	5,815,051
Business Acquisition, Equity Interest Issued or Issuable, Value Assigned			$ 119,400