Acquisitions - Heritage Oaks Bancorp - Schedule (Details) - USD ($) $ in Thousands	Apr. 01, 2017	Jun. 30, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Goodwill		$ 370,564	$ 102,490
Heritage Oaks Bancorp
Business Acquisition [Line Items]
Cash and cash equivalents	$ 78,728
Investment securities	442,923
FHLB Stock	9,739
Loans, gross	1,364,688
Allowance for loan losses	0
Fixed assets	34,902
Core deposit intangible	28,123
Deferred income taxes	10,559
Other assets	45,475
Total assets acquired	2,015,137
Deposits	1,669,550
Borrowings	139,034
Other Liabilities	8,061
Total liabilities assumed	1,816,645
Excess of assets acquired over liabilities assumed	198,492
Consideration paid	464,982
Capitalized merger-related expense	1,585
Goodwill	268,075
Heritage Oaks Bancorp | Book Value
Business Acquisition [Line Items]
Cash and cash equivalents	78,728
Investment securities	447,520
FHLB Stock	9,739
Loans, gross	1,387,949
Allowance for loan losses	(17,200)
Fixed assets	35,567
Core deposit intangible	0
Deferred income taxes	17,850
Other assets	45,484
Total assets acquired	2,005,637
Deposits	1,668,079
Borrowings	141,996
Other Liabilities	7,290
Total liabilities assumed	1,817,365
Excess of assets acquired over liabilities assumed	188,272
Heritage Oaks Bancorp | Fair Value Adjustments
Business Acquisition [Line Items]
Cash and cash equivalents	0
Investment securities	(4,597)
FHLB Stock	0
Loans, gross	(23,261)
Allowance for loan losses	17,200
Fixed assets	(665)
Core deposit intangible	28,123
Deferred income taxes	(7,291)
Other assets	(9)
Total assets acquired	9,500
Deposits	1,471
Borrowings	(2,962)
Other Liabilities	771
Total liabilities assumed	(720)
Excess of assets acquired over liabilities assumed	$ 10,220