Allowance for Credit Losses - Credit Risk Profiles Based on Payment Activity, Not Subject to Loan Grading (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Loans and Leases Receivable Disclosure [Line Items]
Loans and leases	$ 12,961,999	$ 13,279,097	$ 13,211,650
Residential mortgage
Loans and Leases Receivable Disclosure [Line Items]
Loans and leases	4,083,367	3,690,218
Home equity
Loans and Leases Receivable Disclosure [Line Items]
Loans and leases		841,624
Consumer loans
Loans and Leases Receivable Disclosure [Line Items]
Loans and leases		1,353,842
Residential and consumer
Loans and Leases Receivable Disclosure [Line Items]
Loans and leases	12,961,999	13,279,097
Residential Mortgage
Loans and Leases Receivable Disclosure [Line Items]
Loans and leases	4,083,367	3,690,218	4,662,175
Residential Mortgage | Home equity
Loans and Leases Receivable Disclosure [Line Items]
Loans and leases		4,531,842
Home equity Line
Loans and Leases Receivable Disclosure [Line Items]
Loans and leases	876,608	841,624
Consumer
Loans and Leases Receivable Disclosure [Line Items]
Loans and leases	1,229,939	$ 1,353,842	$ 1,620,556
Residential Mortgage.
Loans and Leases Receivable Disclosure [Line Items]
Loans and leases	4,959,975
Home Equity Loans and Lines of Credit
Loans and Leases Receivable Disclosure [Line Items]
Loans and leases	$ 876,608