Allowance for Credit Losses and Credit Quality of Loans, Past Due Loans (Details) $ in Thousands	Sep. 30, 2021 USD ($) Relationship	Dec. 31, 2020 USD ($) Relationship
Allowance for Credit Losses and Credit Quality of Loans [Abstract]
Individually evaluated loans, number of relationships | Relationship	5	5
Individually evaluated loans, amortized cost	$ 12,500	$ 15,200
Individually evaluated loans, allowance for credit losses	1,300	3,200
Past Due and Nonperforming Loans [Abstract]
Nonaccrual	35,737	44,647
Recorded total loans	7,566,442	7,498,885
Loans in non-accrual without an allowance for credit losses	0	0
Past Due [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	34,731	27,806
31-60 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	26,084	18,472
61-90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	5,707	6,185
Greater Than 90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	2,940	3,149
Current [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	7,495,974	7,426,432
C&I [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	1,117,805	1,125,616
CRE [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	2,558,231	2,412,285
PPP [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	276,195	430,810
Auto [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	839,137	892,105
Other Consumer [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	754,737	648,154
Commercial Loans [Member]
Past Due and Nonperforming Loans [Abstract]
Nonaccrual	20,345	24,249
Recorded total loans	3,952,231	3,968,711
Commercial Loans [Member] | Past Due [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	16,578	5,804
Commercial Loans [Member] | 31-60 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	14,277	2,917
Commercial Loans [Member] | 61-90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	1,860	2,394
Commercial Loans [Member] | Greater Than 90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	441	493
Commercial Loans [Member] | Current [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	3,915,308	3,938,658
Commercial Loans [Member] | C&I [Member]
Past Due and Nonperforming Loans [Abstract]
Nonaccrual	4,261	4,278
Recorded total loans	1,117,805	1,125,616
Commercial Loans [Member] | C&I [Member] | Past Due [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	2,624	4,652
Commercial Loans [Member] | C&I [Member] | 31-60 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	2,518	2,235
Commercial Loans [Member] | C&I [Member] | 61-90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	106	2,394
Commercial Loans [Member] | C&I [Member] | Greater Than 90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	0	23
Commercial Loans [Member] | C&I [Member] | Current [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	1,110,920	1,116,686
Commercial Loans [Member] | CRE [Member]
Past Due and Nonperforming Loans [Abstract]
Nonaccrual	16,084	19,971
Recorded total loans	2,558,231	2,412,285
Commercial Loans [Member] | CRE [Member] | Past Due [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	13,954	1,152
Commercial Loans [Member] | CRE [Member] | 31-60 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	11,759	682
Commercial Loans [Member] | CRE [Member] | 61-90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	1,754	0
Commercial Loans [Member] | CRE [Member] | Greater Than 90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	441	470
Commercial Loans [Member] | CRE [Member] | Current [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	2,528,193	2,391,162
Commercial Loans [Member] | PPP [Member]
Past Due and Nonperforming Loans [Abstract]
Nonaccrual	0	0
Recorded total loans	276,195	430,810
Commercial Loans [Member] | PPP [Member] | Past Due [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	0	0
Commercial Loans [Member] | PPP [Member] | 31-60 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	0	0
Commercial Loans [Member] | PPP [Member] | 61-90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	0	0
Commercial Loans [Member] | PPP [Member] | Greater Than 90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	0	0
Commercial Loans [Member] | PPP [Member] | Current [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	276,195	430,810
Consumer Loans [Member]
Past Due and Nonperforming Loans [Abstract]
Nonaccrual	1,617	3,020
Recorded total loans	1,593,874	1,540,259
Consumer Loans [Member] | Past Due [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	14,431	18,456
Consumer Loans [Member] | 31-60 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	9,928	12,836
Consumer Loans [Member] | 61-90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	3,113	3,482
Consumer Loans [Member] | Greater Than 90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	1,390	2,138
Consumer Loans [Member] | Current [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	1,577,826	1,518,783
Consumer Loans [Member] | Auto [Member]
Past Due and Nonperforming Loans [Abstract]
Nonaccrual	1,407	2,730
Recorded total loans	839,137	892,105
Consumer Loans [Member] | Auto [Member] | Past Due [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	8,145	11,544
Consumer Loans [Member] | Auto [Member] | 31-60 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	6,455	9,125
Consumer Loans [Member] | Auto [Member] | 61-90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	1,110	1,553
Consumer Loans [Member] | Auto [Member] | Greater Than 90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	580	866
Consumer Loans [Member] | Auto [Member] | Current [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	829,585	877,831
Consumer Loans [Member] | Other Consumer [Member]
Past Due and Nonperforming Loans [Abstract]
Nonaccrual	210	290
Recorded total loans	754,737	648,154
Consumer Loans [Member] | Other Consumer [Member] | Past Due [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	6,286	6,912
Consumer Loans [Member] | Other Consumer [Member] | 31-60 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	3,473	3,711
Consumer Loans [Member] | Other Consumer [Member] | 61-90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	2,003	1,929
Consumer Loans [Member] | Other Consumer [Member] | Greater Than 90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	810	1,272
Consumer Loans [Member] | Other Consumer [Member] | Current [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	748,241	640,952
Residential [Member]
Past Due and Nonperforming Loans [Abstract]
Nonaccrual	13,775	17,378
Recorded total loans	2,020,337	1,989,915
Residential [Member] | Past Due [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	3,722	3,546
Residential [Member] | 31-60 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	1,879	2,719
Residential [Member] | 61-90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	734	309
Residential [Member] | Greater Than 90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	1,109	518
Residential [Member] | Current [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	$ 2,002,840	$ 1,968,991