Allowance for Credit Losses and Credit Quality of Loans, Past Due Loans (Details) $ in Thousands	Jun. 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	$ 15,000	$ 15,200
Individually evaluated loans, allowance for credit losses	3,400	3,200
Past Due and Nonperforming Loans [Abstract]
Nonaccrual	40,550	44,647
Recorded total loans	7,517,627	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	19,517	27,806
31-60 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	11,845	18,472
61-90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	5,097	6,185
Greater Than 90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	2,575	3,149
Current [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	7,457,560	7,426,432
C&I [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	1,144,930	1,125,616
CRE [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	2,498,951	2,412,285
PPP [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	359,738	430,810
Auto [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	863,107	892,105
Other Consumer [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	662,700	648,154
Commercial Loans [Member]
Past Due and Nonperforming Loans [Abstract]
Nonaccrual	23,867	24,249
Recorded total loans	4,003,619	3,968,711
Commercial Loans [Member] | Past Due [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	3,489	5,804
Commercial Loans [Member] | 31-60 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	292	2,917
Commercial Loans [Member] | 61-90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	1,701	2,394
Commercial Loans [Member] | Greater Than 90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	1,496	493
Commercial Loans [Member] | Current [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	3,976,263	3,938,658
Commercial Loans [Member] | C&I [Member]
Past Due and Nonperforming Loans [Abstract]
Nonaccrual	4,908	4,278
Recorded total loans	1,144,930	1,125,616
Commercial Loans [Member] | C&I [Member] | Past Due [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	1,818	4,652
Commercial Loans [Member] | C&I [Member] | 31-60 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	292	2,235
Commercial Loans [Member] | C&I [Member] | 61-90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	30	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	1,496	23
Commercial Loans [Member] | C&I [Member] | Current [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	1,138,204	1,116,686
Commercial Loans [Member] | CRE [Member]
Past Due and Nonperforming Loans [Abstract]
Nonaccrual	18,959	19,971
Recorded total loans	2,498,951	2,412,285
Commercial Loans [Member] | CRE [Member] | Past Due [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	1,671	1,152
Commercial Loans [Member] | CRE [Member] | 31-60 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	0	682
Commercial Loans [Member] | CRE [Member] | 61-90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	1,671	0
Commercial Loans [Member] | CRE [Member] | Greater Than 90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	0	470
Commercial Loans [Member] | CRE [Member] | Current [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	2,478,321	2,391,162
Commercial Loans [Member] | PPP [Member]
Past Due and Nonperforming Loans [Abstract]
Nonaccrual	0	0
Recorded total loans	359,738	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	359,738	430,810
Consumer Loans [Member]
Past Due and Nonperforming Loans [Abstract]
Nonaccrual	1,441	3,020
Recorded total loans	1,525,807	1,540,259
Consumer Loans [Member] | Past Due [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	12,695	18,456
Consumer Loans [Member] | 31-60 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	9,257	12,836
Consumer Loans [Member] | 61-90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	2,466	3,482
Consumer Loans [Member] | Greater Than 90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	972	2,138
Consumer Loans [Member] | Current [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	1,511,671	1,518,783
Consumer Loans [Member] | Auto [Member]
Past Due and Nonperforming Loans [Abstract]
Nonaccrual	1,273	2,730
Recorded total loans	863,107	892,105
Consumer Loans [Member] | Auto [Member] | Past Due [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	7,328	11,544
Consumer Loans [Member] | Auto [Member] | 31-60 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	6,233	9,125
Consumer Loans [Member] | Auto [Member] | 61-90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	878	1,553
Consumer Loans [Member] | Auto [Member] | Greater Than 90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	217	866
Consumer Loans [Member] | Auto [Member] | Current [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	854,506	877,831
Consumer Loans [Member] | Other Consumer [Member]
Past Due and Nonperforming Loans [Abstract]
Nonaccrual	168	290
Recorded total loans	662,700	648,154
Consumer Loans [Member] | Other Consumer [Member] | Past Due [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	5,367	6,912
Consumer Loans [Member] | Other Consumer [Member] | 31-60 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	3,024	3,711
Consumer Loans [Member] | Other Consumer [Member] | 61-90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	1,588	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	755	1,272
Consumer Loans [Member] | Other Consumer [Member] | Current [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	657,165	640,952
Residential [Member]
Past Due and Nonperforming Loans [Abstract]
Nonaccrual	15,242	17,378
Recorded total loans	1,988,201	1,989,915
Residential [Member] | Past Due [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	3,333	3,546
Residential [Member] | 31-60 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	2,296	2,719
Residential [Member] | 61-90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	930	309
Residential [Member] | Greater Than 90 Days Past Due Accruing [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	107	518
Residential [Member] | Current [Member]
Past Due and Nonperforming Loans [Abstract]
Recorded total loans	$ 1,969,626	$ 1,968,991