Loans and Leases and the Allowance for Credit Losses - Schedule of Aging Analysis by Class of Loan and Lease Portfolio (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Non- Accrual	$ 16,149	$ 17,380
Total Past Due and Non- Accrual	52,619	82,527
Current	11,887,401	10,908,365
Total Loans and Leases	11,940,020	10,990,892
Non- Accrual Loans and Leases that are Current	8,355	11,506
Commercial
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Non- Accrual	8,968	10,074
Total Past Due and Non- Accrual	9,218	26,626
Current	5,091,468	4,187,201
Total Loans and Leases	5,100,686	4,213,827
Non- Accrual Loans and Leases that are Current	5,268	9,665
Commercial | Commercial and Industrial
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Non- Accrual	441	830
Total Past Due and Non- Accrual	691	13,512
Current	1,874,602	1,365,640
Total Loans and Leases	1,875,293	1,379,152
Non- Accrual Loans and Leases that are Current	285	421
Commercial | Commercial Mortgage
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Non- Accrual	8,527	9,244
Total Past Due and Non- Accrual	8,527	12,242
Current	2,846,302	2,505,809
Total Loans and Leases	2,854,829	2,518,051
Non- Accrual Loans and Leases that are Current	4,983	9,244
Commercial | Construction
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Non- Accrual	0	0
Total Past Due and Non- Accrual	0	152
Current	259,798	194,018
Total Loans and Leases	259,798	194,170
Non- Accrual Loans and Leases that are Current	0	0
Commercial | Lease Financing
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Non- Accrual	0	0
Total Past Due and Non- Accrual	0	720
Current	110,766	121,734
Total Loans and Leases	110,766	122,454
Non- Accrual Loans and Leases that are Current	0	0
Consumer
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Non- Accrual	7,181	7,306
Total Past Due and Non- Accrual	43,401	55,901
Current	6,795,933	6,721,164
Total Loans and Leases	6,839,334	6,777,065
Non- Accrual Loans and Leases that are Current	3,087	1,841
Consumer | Other
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Non- Accrual	0	0
Total Past Due and Non- Accrual	5,328	7,065
Current	390,155	482,541
Total Loans and Leases	395,483	489,606
Non- Accrual Loans and Leases that are Current	0	0
Consumer | Residential Mortgage
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Non- Accrual	3,223	4,125
Total Past Due and Non- Accrual	14,629	14,131
Current	4,115,884	3,876,969
Total Loans and Leases	4,130,513	3,891,100
Non- Accrual Loans and Leases that are Current	2,100	1,429
Consumer | Home Equity
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Non- Accrual	3,958	3,181
Total Past Due and Non- Accrual	13,946	13,535
Current	1,590,592	1,662,538
Total Loans and Leases	1,604,538	1,676,073
Non- Accrual Loans and Leases that are Current	987	412
Consumer | Automobile
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Non- Accrual	0	0
Total Past Due and Non- Accrual	9,498	21,170
Current	699,302	699,116
Total Loans and Leases	708,800	720,286
Non- Accrual Loans and Leases that are Current	0	0
30 - 59 Days Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	16,577	45,964
30 - 59 Days Past Due | Commercial
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	191	16,353
30 - 59 Days Past Due | Commercial | Commercial and Industrial
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	191	12,534
30 - 59 Days Past Due | Commercial | Commercial Mortgage
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	0	2,998
30 - 59 Days Past Due | Commercial | Construction
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	0	101
30 - 59 Days Past Due | Commercial | Lease Financing
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	0	720
30 - 59 Days Past Due | Consumer
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	16,386	29,611
30 - 59 Days Past Due | Consumer | Other
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	2,556	3,498
30 - 59 Days Past Due | Consumer | Residential Mortgage
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	4,049	6,097
30 - 59 Days Past Due | Consumer | Home Equity
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	3,423	3,949
30 - 59 Days Past Due | Consumer | Automobile
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	6,358	16,067
60 - 89 Days Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	9,347	10,777
60 - 89 Days Past Due | Commercial
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	59	199
60 - 89 Days Past Due | Commercial | Commercial and Industrial
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	59	148
60 - 89 Days Past Due | Commercial | Commercial Mortgage
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	0	0
60 - 89 Days Past Due | Commercial | Construction
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	0	51
60 - 89 Days Past Due | Commercial | Lease Financing
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	0	0
60 - 89 Days Past Due | Consumer
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	9,288	10,578
60 - 89 Days Past Due | Consumer | Other
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	1,612	2,074
60 - 89 Days Past Due | Consumer | Residential Mortgage
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	2,083	2,070
60 - 89 Days Past Due | Consumer | Home Equity
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	3,378	2,280
60 - 89 Days Past Due | Consumer | Automobile
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	2,215	4,154
Past Due 90 Days or More
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	10,546	8,406
Past Due 90 Days or More | Commercial
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	0	0
Past Due 90 Days or More | Commercial | Commercial and Industrial
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	0	0
Past Due 90 Days or More | Commercial | Commercial Mortgage
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	0	0
Past Due 90 Days or More | Commercial | Construction
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	0	0
Past Due 90 Days or More | Commercial | Lease Financing
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	0	0
Past Due 90 Days or More | Consumer
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	10,546	8,406
Past Due 90 Days or More | Consumer | Other
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	1,160	1,493
Past Due 90 Days or More | Consumer | Residential Mortgage
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	5,274	1,839
Past Due 90 Days or More | Consumer | Home Equity
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	3,187	4,125
Past Due 90 Days or More | Consumer | Automobile
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Days Past Due	$ 925	$ 949