Allowance for Credit Losses and Credit Quality of Loans (Details) - USD ($) $ in Thousands		Mar. 31, 2020	Dec. 31, 2019
Allowance for Credit Losses [Abstract]
Allowance for credit losses	[1]	$ 100,000
Retained earnings		678,611	$ 696,214
ASU 2016-13 [Member]
Allowance for Credit Losses [Abstract]
Allowance for credit losses		100,000	75,999
AIR on loans		$ 54,000
ASU 2016-13 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Allowance for Credit Losses [Abstract]
Allowance for credit losses			3,000
Retained earnings			(4,300)
Deferred tax asset			(1,500)
ASU 2016-13 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | Loans [Member]
Allowance for Credit Losses [Abstract]
Allowance for credit losses			3,000
Retained earnings			(2,300)
Deferred tax asset			$ 700

[1] Beginning January 1, 2020, calculation is based on current expected loss methodology. Prior to January 1, 2020, calculation was based on incurred loss methodology.