Allowance for Credit Losses - Loans on Nonaccrual Status and Loans Past Due 90 Days or More and Still Accruing (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022 USD ($) loan	Dec. 31, 2021 USD ($) loan
Financing Receivable, Nonaccrual [Line Items]
Beginning of Period Nonaccrual	$ 66,291	$ 146,774
End of Period Nonaccrual	52,524	66,291
Nonaccrual With No Related Allowance	24,824	37,469
Past Due 90+ Days Still Accruing	1,116	0
Interest income recognized on nonaccrual	$ 173	$ 1,128
Number of modified loans | loan	3	8
Modified loans	$ 12,500	$ 28,800
Past Due 90+ Days Still Accruing
Financing Receivable, Nonaccrual [Line Items]
Number of modified loans | loan	5
Modified loans	$ 1,100
Commercial | Commercial real estate
Financing Receivable, Nonaccrual [Line Items]
Beginning of Period Nonaccrual	31,488	101,070
End of Period Nonaccrual	25,790	31,488
Nonaccrual With No Related Allowance	21,058	28,046
Past Due 90+ Days Still Accruing	0	0
Interest income recognized on nonaccrual	32	158
Commercial | Commercial and industrial
Financing Receivable, Nonaccrual [Line Items]
Beginning of Period Nonaccrual	15,239	16,985
End of Period Nonaccrual	10,570	15,239
Nonaccrual With No Related Allowance	1,700	5,707
Past Due 90+ Days Still Accruing	529	0
Interest income recognized on nonaccrual	32	74
Commercial | Commercial construction
Financing Receivable, Nonaccrual [Line Items]
Beginning of Period Nonaccrual	2,471	384
End of Period Nonaccrual	864	2,471
Nonaccrual With No Related Allowance	480	2,020
Past Due 90+ Days Still Accruing	0	0
Interest income recognized on nonaccrual	0	(28)
Commercial | Business banking
Financing Receivable, Nonaccrual [Line Items]
Beginning of Period Nonaccrual	9,641	17,122
End of Period Nonaccrual	7,997	9,641
Nonaccrual With No Related Allowance	1,586	1,696
Past Due 90+ Days Still Accruing	587	0
Interest income recognized on nonaccrual	48	427
Consumer | Consumer real estate
Financing Receivable, Nonaccrual [Line Items]
Beginning of Period Nonaccrual	7,294	11,117
End of Period Nonaccrual	7,178	7,294
Nonaccrual With No Related Allowance	0	0
Past Due 90+ Days Still Accruing	0	0
Interest income recognized on nonaccrual	61	496
Consumer | Other consumer
Financing Receivable, Nonaccrual [Line Items]
Beginning of Period Nonaccrual	158	96
End of Period Nonaccrual	125	158
Nonaccrual With No Related Allowance	0	0
Past Due 90+ Days Still Accruing	0	0
Interest income recognized on nonaccrual	$ 0	$ 1