Allowance for Credit Losses - Rollforward of the Reserve for Unfunded Commitments (Details) - Reserve for unfunded commitments - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Reserve for unfunded commitments:
Reserve for unfunded commitments, beginning balance	$ 30,322	$ 30,603
Increase (decrease) in Provision	(1,364)	3,500
Reserve for unfunded commitments, ending balance	28,958	34,103
Commercial and Industrial
Reserve for unfunded commitments:
Reserve for unfunded commitments, beginning balance	8,615	11,719
Increase (decrease) in Provision	693	4,410
Reserve for unfunded commitments, ending balance	9,308	16,129
Commercial real estate
Reserve for unfunded commitments:
Reserve for unfunded commitments, beginning balance	2,114	1,328
Increase (decrease) in Provision	(325)	(216)
Reserve for unfunded commitments, ending balance	1,789	1,112
Construction
Reserve for unfunded commitments:
Reserve for unfunded commitments, beginning balance	8,963	9,037
Increase (decrease) in Provision	(917)	(724)
Reserve for unfunded commitments, ending balance	8,046	8,313
Residential mortgage
Reserve for unfunded commitments:
Reserve for unfunded commitments, beginning balance	15	2
Increase (decrease) in Provision	(12)	(2)
Reserve for unfunded commitments, ending balance	3
Home equity line
Reserve for unfunded commitments:
Reserve for unfunded commitments, beginning balance	10,546	8,452
Increase (decrease) in Provision	(780)	48
Reserve for unfunded commitments, ending balance	9,766	8,500
Consumer
Reserve for unfunded commitments:
Reserve for unfunded commitments, beginning balance	69	65
Increase (decrease) in Provision	(23)	(16)
Reserve for unfunded commitments, ending balance	$ 46	$ 49