Allowance for Credit Losses - Reserve for Unfunded Commitments (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Reserve for unfunded commitments:
Adoption of ASU 2016-13			$ 770
Commercial and Industrial
Reserve for unfunded commitments:
Adoption of ASU 2016-13			(16,105)
Commercial real estate
Reserve for unfunded commitments:
Adoption of ASU 2016-13			10,559
Construction
Reserve for unfunded commitments:
Adoption of ASU 2016-13			(1,803)
Lease financing
Reserve for unfunded commitments:
Adoption of ASU 2016-13			207
Consumer
Reserve for unfunded commitments:
Adoption of ASU 2016-13			15,575
Reserve for unfunded commitments
Reserve for unfunded commitments:
Reserve for unfunded commitments, beginning balance	$ 17,251	$ 600
Adoption of ASU 2016-13			16,300
Increase (decrease) in Provision	5,953	6,304
Reserve for unfunded commitments, ending balance	23,204	23,204
Reserve for unfunded commitments | Commercial and Industrial
Reserve for unfunded commitments:
Reserve for unfunded commitments, beginning balance	4,791
Adoption of ASU 2016-13			5,390
Increase (decrease) in Provision	3,390	2,791
Reserve for unfunded commitments, ending balance	8,181	8,181
Reserve for unfunded commitments | Commercial real estate
Reserve for unfunded commitments:
Reserve for unfunded commitments, beginning balance	696
Adoption of ASU 2016-13			778
Increase (decrease) in Provision	472	390
Reserve for unfunded commitments, ending balance	1,168	1,168
Reserve for unfunded commitments | Construction
Reserve for unfunded commitments:
Reserve for unfunded commitments, beginning balance	4,813
Adoption of ASU 2016-13			4,119
Increase (decrease) in Provision	1,095	1,789
Reserve for unfunded commitments, ending balance	5,908	5,908
Reserve for unfunded commitments | Residential mortgage
Reserve for unfunded commitments:
Reserve for unfunded commitments, beginning balance	1
Adoption of ASU 2016-13			7
Increase (decrease) in Provision	2	(4)
Reserve for unfunded commitments, ending balance	3	3
Reserve for unfunded commitments | Home equity
Reserve for unfunded commitments:
Reserve for unfunded commitments, beginning balance	6,927
Adoption of ASU 2016-13			6,587
Increase (decrease) in Provision	963	1,303
Reserve for unfunded commitments, ending balance	7,890	7,890
Reserve for unfunded commitments | Consumer
Reserve for unfunded commitments:
Reserve for unfunded commitments, beginning balance	23	600
Adoption of ASU 2016-13			$ (581)
Increase (decrease) in Provision	31	35
Reserve for unfunded commitments, ending balance	$ 54	$ 54