Acquisitions - Security California Bancorp Schedule (Details) - USD ($) $ in Thousands	Jan. 31, 2016	Jun. 30, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Goodwill		$ 370,564	$ 102,490
Security California Bancorp
Business Acquisition [Line Items]
Cash and cash equivalents	$ 40,947
Interest-bearing deposits with financial institutions	1,972
Investment securities	190,254
Loans, gross	456,158
Allowance for loan losses	0
Fixed assets	4,190
Core deposit intangible	4,319
Deferred income taxes	6,748
Other assets	9,362
Total assets acquired	713,950
Deposits	636,591
Other Liabilities	8,843
Total liabilities assumed	645,434
Excess of assets acquired over liabilities assumed	68,516
Consideration paid	120,174
Goodwill	51,658
Security California Bancorp | Book Value
Business Acquisition [Line Items]
Cash and cash equivalents	40,947
Interest-bearing deposits with financial institutions	1,972
Investment securities	191,881
Loans, gross	467,197
Allowance for loan losses	(7,399)
Fixed assets	5,335
Core deposit intangible	493
Deferred income taxes	5,618
Other assets	10,589
Total assets acquired	716,633
Deposits	636,450
Other Liabilities	9,063
Total liabilities assumed	645,513
Excess of assets acquired over liabilities assumed	71,120
Security California Bancorp | Fair Value Adjustments
Business Acquisition [Line Items]
Cash and cash equivalents	0
Interest-bearing deposits with financial institutions	0
Investment securities	(1,627)
Loans, gross	(11,039)
Allowance for loan losses	7,399
Fixed assets	(1,145)
Core deposit intangible	3,826
Deferred income taxes	1,130
Other assets	(1,227)
Total assets acquired	(2,683)
Deposits	141
Other Liabilities	(220)
Total liabilities assumed	(79)
Excess of assets acquired over liabilities assumed	$ (2,604)