Nature of Operations and Summary of Significant Accounting Policies (Details Textual)			12 Months Ended
	Jan. 01, 2020 USD ($)	Jan. 01, 2019 USD ($)	Dec. 31, 2019 USD ($) reportable_segment bank_branch		Dec. 31, 2018 USD ($)		Dec. 31, 2017 USD ($)
Business Acquisition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Net Income			$ 938,000	[1]			$ 291,000	[2]
Transfer of Portfolio Loans and Leases to Held-for-sale			$ 25,124,000		$ 0		481,100,000
Allowance For Credit Losses, Look-back Period for Estimation			44
Fair Value Hedges, Net			$ 0
Derivative, Notional Amount			$ 91,100,000
Number of Reportable Segments | reportable_segment			1
Provision for losses on foreclosed assets			$ 78,000		74,000		2,138,000
Core Deposits [Member] | Minimum
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life			7 years
Core Deposits [Member] | Maximum
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life			10 years
Customer Relationships [Member] | Minimum
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life			4 years
Customer Relationships [Member] | Maximum
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life			7 years
Furniture and Fixtures [Member] | Minimum
Business Acquisition [Line Items]
Property, Plant and Equipment, Useful Life			3 years
Furniture and Fixtures [Member] | Maximum
Business Acquisition [Line Items]
Property, Plant and Equipment, Useful Life			7 years
Building [Member]
Business Acquisition [Line Items]
Property, Plant and Equipment, Useful Life			30 years
Loans Under $250,000
Business Acquisition [Line Items]
Financing Receivable, Collectively Evaluated for Impairment			$ 250,000
CALIFORNIA
Business Acquisition [Line Items]
Retail Branch Locations | bank_branch			74
NORTH CAROLINA
Business Acquisition [Line Items]
Retail Branch Locations | bank_branch			1
COLORADO
Business Acquisition [Line Items]
Retail Branch Locations | bank_branch			1
Retained Earnings [Member]
Business Acquisition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Net Income		$ 938,000	$ 938,000	[1]	$ (6,136,000)	[3]	$ (420,000)	[2]
PRSU
Business Acquisition [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Performance Period			3 years
PRSU | Maximum
Business Acquisition [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage			200.00%
Target vesting 1 | PRSU | Minimum
Business Acquisition [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage			0.00%
Target vesting 1 | PRSU | Maximum
Business Acquisition [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage			150.00%
Target vesting 2 | PRSU | Minimum
Business Acquisition [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage			0.00%
Target vesting 2 | PRSU | Maximum
Business Acquisition [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage			200.00%
Limited Partnership [Member] | Minimum
Business Acquisition [Line Items]
Equity Method Investment, Ownership Percentage			5.00%
Purchased Credit Impaired Loans and Leases [Member]
Business Acquisition [Line Items]
Concentration Risk, Percentage					0.40%
Equity Securities | Minimum
Business Acquisition [Line Items]
Equity Method Investment, Ownership Percentage			20.00%
Equity Securities | Maximum
Business Acquisition [Line Items]
Equity Method Investment, Ownership Percentage			50.00%
Accounting Standards Update 2016-13 [Member]
Business Acquisition [Line Items]
Provision for losses on foreclosed assets	$ 7,300,000
Financing Receivable, Credit Loss, Adjustment, Percent	4.20%
Cumulative Effect of New Accounting Principle in Period of Adoption	$ 5,300,000

[1] Impact due to adoption on January 1, 2019 of ASU 2016-02, "Leases (Topic 842)," and the related amendments.

[2] Impact due to adoption on January 1, 2017 of ASU 2016-09, "Improvements to Employee Share-Based Payment Accounting."

[3] Impact due to adoption on January 1, 2018 of ASU 2016-01, "Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities" and ASU 2018-02, "Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income."