Allowance for Credit Losses and Credit Quality of Loans, Credit Quality Indicators (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Financing Receivable, Credit Quality Indicator [Line Items]
Minimum number of days past due for loans to be considered nonperforming	90 days
Credit Quality by Loan Class [Abstract]
2021/2020	$ 1,683,857	$ 1,927,429
2020/2019	1,278,131	1,312,819
2019/2018	1,098,762	949,810
2018/2017	743,460	750,728
2017/2016	578,691	515,688
Prior	1,427,696	1,262,066
Revolving Loans Amortized Cost Basis	716,030	749,657
Revolving Loans Converted to Term	39,815	30,688
Total	7,566,442	7,498,885
C&I [Member]
Credit Quality by Loan Class [Abstract]
2021/2020	258,221	352,323
2020/2019	260,929	195,227
2019/2018	140,438	106,502
2018/2017	76,173	50,153
2017/2016	29,464	35,040
Prior	47,283	39,712
Revolving Loans Amortized Cost Basis	293,744	346,233
Revolving Loans Converted to Term	11,553	426
Total	1,117,805	1,125,616
C&I [Member] | Pass [Member]
Credit Quality by Loan Class [Abstract]
2021/2020	258,044	331,921
2020/2019	256,285	182,329
2019/2018	127,995	91,230
2018/2017	71,024	41,856
2017/2016	23,541	32,625
Prior	40,962	32,609
Revolving Loans Amortized Cost Basis	282,471	322,674
Revolving Loans Converted to Term	6,724	412
Total	1,067,046	1,035,656
C&I [Member] | Special Mention [Member]
Credit Quality by Loan Class [Abstract]
2021/2020	163	20,064
2020/2019	4,277	6,534
2019/2018	5,157	5,053
2018/2017	3,339	4,702
2017/2016	3,063	1,624
Prior	3,381	2,830
Revolving Loans Amortized Cost Basis	8,477	13,614
Revolving Loans Converted to Term	0	0
Total	27,857	54,421
C&I [Member] | Substandard [Member]
Credit Quality by Loan Class [Abstract]
2021/2020	14	338
2020/2019	367	6,364
2019/2018	7,286	10,219
2018/2017	1,684	3,388
2017/2016	2,675	791
Prior	2,939	4,272
Revolving Loans Amortized Cost Basis	2,796	9,945
Revolving Loans Converted to Term	4,829	14
Total	22,590	35,331
C&I [Member] | Doubtful [Member]
Credit Quality by Loan Class [Abstract]
2021/2020	0	0
2020/2019	0	0
2019/2018	0	0
2018/2017	126	207
2017/2016	185	0
Prior	1	1
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total	312	208
CRE [Member]
Credit Quality by Loan Class [Abstract]
2021/2020	325,888	472,506
2020/2019	454,150	412,425
2019/2018	427,993	296,712
2018/2017	269,664	342,604
2017/2016	297,505	255,045
Prior	611,369	496,867
Revolving Loans Amortized Cost Basis	155,001	115,926
Revolving Loans Converted to Term	16,661	20,200
Total	2,558,231	2,412,285
CRE [Member] | Pass [Member]
Credit Quality by Loan Class [Abstract]
2021/2020	325,092	469,919
2020/2019	453,138	361,187
2019/2018	390,834	256,154
2018/2017	249,362	271,874
2017/2016	264,620	212,197
Prior	486,685	383,690
Revolving Loans Amortized Cost Basis	152,622	113,128
Revolving Loans Converted to Term	16,661	4,034
Total	2,339,014	2,072,183
CRE [Member] | Special Mention [Member]
Credit Quality by Loan Class [Abstract]
2021/2020	796	2,051
2020/2019	933	44,034
2019/2018	21,467	22,260
2018/2017	4,747	55,039
2017/2016	20,344	36,830
Prior	67,530	43,537
Revolving Loans Amortized Cost Basis	1,140	1,297
Revolving Loans Converted to Term	0	11,524
Total	116,957	216,572
CRE [Member] | Substandard [Member]
Credit Quality by Loan Class [Abstract]
2021/2020	0	536
2020/2019	79	5,307
2019/2018	15,692	18,298
2018/2017	15,555	15,691
2017/2016	12,541	6,018
Prior	50,428	62,168
Revolving Loans Amortized Cost Basis	1,239	1,501
Revolving Loans Converted to Term	0	4,642
Total	95,534	114,161
CRE [Member] | Doubtful [Member]
Credit Quality by Loan Class [Abstract]
2021/2020	0	0
2020/2019	0	1,897
2019/2018	0	0
2018/2017	0	0
2017/2016	0	0
Prior	6,726	7,472
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total	6,726	9,369
PPP [Member]
Credit Quality by Loan Class [Abstract]
2021/2020	256,940	430,810
2020/2019	19,255	0
2019/2018	0	0
2018/2017	0	0
2017/2016	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total	276,195	430,810
PPP [Member] | Pass [Member]
Credit Quality by Loan Class [Abstract]
2021/2020	256,940	430,810
2020/2019	19,255	0
2019/2018	0	0
2018/2017	0	0
2017/2016	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total	276,195	430,810
Auto [Member]
Credit Quality by Loan Class [Abstract]
2021/2020	280,953	198,240
2020/2019	145,905	315,174
2019/2018	212,633	202,985
2018/2017	121,646	116,502
2017/2016	59,316	45,932
Prior	18,684	13,250
Revolving Loans Amortized Cost Basis	0	22
Revolving Loans Converted to Term	0	0
Total	839,137	892,105
Auto [Member] | Performing [Member]
Credit Quality by Loan Class [Abstract]
2021/2020	280,805	197,881
2020/2019	145,585	314,034
2019/2018	211,921	201,850
2018/2017	121,108	115,977
2017/2016	59,047	45,495
Prior	18,684	13,250
Revolving Loans Amortized Cost Basis	0	22
Revolving Loans Converted to Term	0	0
Total	837,150	888,509
Auto [Member] | Nonperforming [Member]
Credit Quality by Loan Class [Abstract]
2021/2020	148	359
2020/2019	320	1,140
2019/2018	712	1,135
2018/2017	538	525
2017/2016	269	437
Prior	0	0
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total	1,987	3,596
Other Consumer [Member]
Credit Quality by Loan Class [Abstract]
2021/2020	298,601	234,967
2020/2019	166,401	178,829
2019/2018	129,189	127,856
2018/2017	88,407	55,941
2017/2016	35,049	14,345
Prior	18,556	17,547
Revolving Loans Amortized Cost Basis	18,519	18,598
Revolving Loans Converted to Term	15	71
Total	754,737	648,154
Other Consumer [Member] | Performing [Member]
Credit Quality by Loan Class [Abstract]
2021/2020	298,505	234,628
2020/2019	166,111	178,411
2019/2018	128,954	127,549
2018/2017	88,311	55,676
2017/2016	34,858	14,255
Prior	18,447	17,414
Revolving Loans Amortized Cost Basis	18,516	18,588
Revolving Loans Converted to Term	15	71
Total	753,717	646,592
Other Consumer [Member] | Nonperforming [Member]
Credit Quality by Loan Class [Abstract]
2021/2020	96	339
2020/2019	290	418
2019/2018	235	307
2018/2017	96	265
2017/2016	191	90
Prior	109	133
Revolving Loans Amortized Cost Basis	3	10
Revolving Loans Converted to Term	0	0
Total	1,020	1,562
Residential [Member]
Credit Quality by Loan Class [Abstract]
2021/2020	263,254	238,583
2020/2019	231,491	211,164
2019/2018	188,509	215,755
2018/2017	187,570	185,528
2017/2016	157,357	165,326
Prior	731,804	694,690
Revolving Loans Amortized Cost Basis	248,766	268,878
Revolving Loans Converted to Term	11,586	9,991
Total	2,020,337	1,989,915
Residential [Member] | Performing [Member]
Credit Quality by Loan Class [Abstract]
2021/2020	263,254	237,338
2020/2019	229,961	210,505
2019/2018	187,776	213,437
2018/2017	185,798	182,993
2017/2016	155,725	164,424
Prior	722,718	684,495
Revolving Loans Amortized Cost Basis	248,727	268,878
Revolving Loans Converted to Term	11,494	9,991
Total	2,005,453	1,972,061
Residential [Member] | Nonperforming [Member]
Credit Quality by Loan Class [Abstract]
2021/2020	0	1,245
2020/2019	1,530	659
2019/2018	733	2,318
2018/2017	1,772	2,535
2017/2016	1,632	902
Prior	9,086	10,195
Revolving Loans Amortized Cost Basis	39	0
Revolving Loans Converted to Term	92	0
Total	$ 14,884	$ 17,854