Loans, Loans by Past Due Status (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Summarized details of Loans
Financing Receivable, Not Past Due Status	$ 24,077,931	$ 24,202,209
Financing Receivable, Recorded Investment, Nonaccrual Status	130,443	210,854
Loans	24,224,949	24,451,724
Nonaccrual Loans, Current Portion	$ 84,000	$ 128,000
Percent of current nonaccrual loans	65.00%	61.00%
Financing Receivable, Nonaccrual, Interest Income	$ 0	$ 0
Financing Receivable, Nonaccrual, No Allowance	9,000	28,000
30-59 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	12,754	18,077
60-89 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	2,558	18,985
90+ Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	1,263	1,598
PPP
Summarized details of Loans
Financing Receivable, Not Past Due Status	65,941	767,757
Financing Receivable, Recorded Investment, Nonaccrual Status	46	0
Loans	66,070	767,757
PPP | 30-59 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	40	0
PPP | 60-89 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	43	0
PPP | 90+ Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	0	0
Asset-based Lending
Summarized details of Loans
Financing Receivable, Not Past Due Status	178,027	137,476
Financing Receivable, Recorded Investment, Nonaccrual Status	0	0
Loans	178,027	137,476
Asset-based Lending | 30-59 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	0	0
Asset-based Lending | 60-89 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	0	0
Asset-based Lending | 90+ Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	0	0
Commercial and industrial
Summarized details of Loans
Financing Receivable, Not Past Due Status	8,201,272	7,495,792
Financing Receivable, Recorded Investment, Nonaccrual Status	6,233	61,859
Loans	8,208,289	7,563,945
Commercial and industrial | 30-59 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	579	2,819
Commercial and industrial | 60-89 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	54	3,300
Commercial and industrial | 90+ Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	151	175
Commercial real estate - owner occupied
Summarized details of Loans
Financing Receivable, Not Past Due Status	971,163	899,480
Financing Receivable, Recorded Investment, Nonaccrual Status	0	1,058
Loans	971,326	900,912
Commercial real estate - owner occupied | 30-59 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	163	158
Commercial real estate - owner occupied | 60-89 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	0	215
Commercial real estate - owner occupied | 90+ Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	0	0
Commercial and business lending
Summarized details of Loans
Financing Receivable, Not Past Due Status	9,416,403	9,300,506
Financing Receivable, Recorded Investment, Nonaccrual Status	6,279	62,917
Loans	9,423,711	9,370,091
Commercial and business lending | 30-59 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	781	2,977
Commercial and business lending | 60-89 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	97	3,516
Commercial and business lending | 90+ Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	151	175
Commercial real estate - investor
Summarized details of Loans
Financing Receivable, Not Past Due Status	4,323,276	4,251,571
Financing Receivable, Recorded Investment, Nonaccrual Status	60,677	78,220
Loans	4,384,569	4,342,584
Commercial real estate - investor | 30-59 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	142	1,024
Commercial real estate - investor | 60-89 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	474	11,769
Commercial real estate - investor | 90+ Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	0	0
Real estate construction
Summarized details of Loans
Financing Receivable, Not Past Due Status	1,807,178	1,839,073
Financing Receivable, Recorded Investment, Nonaccrual Status	177	353
Loans	1,808,976	1,840,417
Real estate construction | 30-59 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	1,618	991
Real estate construction | 60-89 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	2	0
Real estate construction | 90+ Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	0	0
Commercial real estate lending
Summarized details of Loans
Financing Receivable, Not Past Due Status	6,130,454	6,090,644
Financing Receivable, Recorded Investment, Nonaccrual Status	60,855	78,573
Loans	6,193,545	6,183,001
Commercial real estate lending | 30-59 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	1,759	2,015
Commercial real estate lending | 60-89 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	477	11,769
Commercial real estate lending | 90+ Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	0	0
Total commercial
Summarized details of Loans
Financing Receivable, Not Past Due Status	15,546,857	15,391,150
Financing Receivable, Recorded Investment, Nonaccrual Status	67,134	141,490
Loans	15,617,256	15,553,091
Total commercial | 30-59 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	2,541	4,992
Total commercial | 60-89 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	573	15,284
Total commercial | 90+ Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	151	175
Residential mortgage
Summarized details of Loans
Financing Receivable, Not Past Due Status	7,505,654	7,808,294
Financing Receivable, Recorded Investment, Nonaccrual Status	55,362	59,337
Loans	7,567,310	7,878,324
Residential mortgage | 30-59 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	5,500	8,975
Residential mortgage | 60-89 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	669	1,410
Residential mortgage | 90+ Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	126	308
Home equity
Summarized details of Loans
Financing Receivable, Not Past Due Status	584,177	692,565
Financing Receivable, Recorded Investment, Nonaccrual Status	7,726	9,888
Loans	595,615	707,255
Home equity | 30-59 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	2,867	3,071
Home equity | 60-89 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	844	1,731
Home equity | 90+ Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	0	0
Other consumer
Summarized details of Loans
Financing Receivable, Not Past Due Status	298,261	299,128
Financing Receivable, Recorded Investment, Nonaccrual Status	170	91
Loans	301,723	301,876
Other consumer | 30-59 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	1,835	998
Other consumer | 60-89 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	472	545
Other consumer | 90+ Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	986	1,115
Auto
Summarized details of Loans
Financing Receivable, Not Past Due Status	142,982	11,072
Financing Receivable, Recorded Investment, Nonaccrual Status	52	49
Loans	143,045	11,177
Auto | 30-59 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	11	41
Auto | 60-89 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	0	15
Auto | 90+ Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	0	0
Total consumer
Summarized details of Loans
Financing Receivable, Not Past Due Status	8,531,074	8,811,060
Financing Receivable, Recorded Investment, Nonaccrual Status	63,309	69,364
Loans	8,607,693	8,898,632
Total consumer | 30-59 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	10,213	13,085
Total consumer | 60-89 Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	1,985	3,701
Total consumer | 90+ Days Past Due
Summarized details of Loans
Financing Receivable, Past Due Status	$ 1,111	$ 1,423