Allowance for Credit Losses and Credit Quality of Loans, Allowance for Credit Losses by Portfolio Segments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Activity in allowance for credit losses by portfolio segment [Roll Forward]
Balance, beginning of period	$ 92,000	$ 110,000
Charge-offs	(4,491)	(4,660)
Recoveries	1,895	2,456
Provision	596	(2,796)
Balance, end of period	90,000	105,000
Commercial Loans [Member]
Activity in allowance for credit losses by portfolio segment [Roll Forward]
Balance, beginning of period	28,941	50,942
Charge-offs	(588)	(242)
Recoveries	93	118
Provision	111	(773)
Balance, end of period	28,557	50,045
Consumer Loans [Member]
Activity in allowance for credit losses by portfolio segment [Roll Forward]
Balance, beginning of period	44,253	37,803
Charge-offs	(3,591)	(4,348)
Recoveries	1,652	2,075
Provision	1,277	(950)
Balance, end of period	43,591	34,580
Residential [Member]
Activity in allowance for credit losses by portfolio segment [Roll Forward]
Balance, beginning of period	18,806	21,255
Charge-offs	(312)	(70)
Recoveries	150	263
Provision	(792)	(1,073)
Balance, end of period	$ 17,852	$ 20,375