Loans Past Due Status (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Summarized details of Loans
Current	$ 24,374,481	$ 24,077,931
Nonaccrual(a)(b)	143,221	130,443
Loans and Leases Receivable, Net of Deferred Income, Total	24,531,926	24,224,949
Nonaccrual Loans, Current Portion	$ 98,000	$ 84,000
Percent of current nonaccrual loans	69.00%	65.00%
Financing Receivable, Nonaccrual, Interest Income	$ 0	$ 0
Financing Receivable, Nonaccrual, No Allowance	24,000	9,000
30-59 Days Past Due
Summarized details of Loans
Total Past Due	11,233	12,754
60-89 Days Past Due
Summarized details of Loans
Total Past Due	1,396	2,558
90+ Days Past Due
Summarized details of Loans
Total Past Due	1,595	1,263
PPP
Summarized details of Loans
Current	17,953	65,941
Nonaccrual(a)(b)	41	46
Loans and Leases Receivable, Net of Deferred Income, Total	17,995	66,070
PPP | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	0	40
PPP | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	1	43
PPP | 90+ Days Past Due
Summarized details of Loans
Total Past Due	0	0
Asset-Based Lending
Summarized details of Loans
Current	231,040	178,027
Nonaccrual(a)(b)	0	0
Loans and Leases Receivable, Net of Deferred Income, Total	231,040	178,027
Asset-Based Lending | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	0	0
Asset-Based Lending | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	0	0
Asset-Based Lending | 90+ Days Past Due
Summarized details of Loans
Total Past Due	0	0
Commercial and industrial
Summarized details of Loans
Current	8,100,945	8,201,272
Nonaccrual(a)(b)	225	6,233
Loans and Leases Receivable, Net of Deferred Income, Total	8,102,380	8,208,289
Commercial and industrial | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	923	579
Commercial and industrial | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	162	54
Commercial and industrial | 90+ Days Past Due
Summarized details of Loans
Total Past Due	125	151
Commercial real estate — owner occupied
Summarized details of Loans
Current	973,374	971,163
Nonaccrual(a)(b)	0	0
Loans and Leases Receivable, Net of Deferred Income, Total	973,572	971,326
Commercial real estate — owner occupied | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	198	163
Commercial real estate — owner occupied | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	0	0
Commercial real estate — owner occupied | 90+ Days Past Due
Summarized details of Loans
Total Past Due	0	0
Commercial and business lending
Summarized details of Loans
Current	9,323,311	9,416,403
Nonaccrual(a)(b)	266	6,279
Loans and Leases Receivable, Net of Deferred Income, Total	9,324,986	9,423,711
Commercial and business lending | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	1,121	781
Commercial and business lending | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	163	97
Commercial and business lending | 90+ Days Past Due
Summarized details of Loans
Total Past Due	125	151
Commercial real estate — investor
Summarized details of Loans
Current	4,388,355	4,323,276
Nonaccrual(a)(b)	80,886	60,677
Loans and Leases Receivable, Net of Deferred Income, Total	4,469,241	4,384,569
Commercial real estate — investor | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	0	142
Commercial real estate — investor | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	0	474
Commercial real estate — investor | 90+ Days Past Due
Summarized details of Loans
Total Past Due	0	0
Real estate construction
Summarized details of Loans
Current	1,759,467	1,807,178
Nonaccrual(a)(b)	609	177
Loans and Leases Receivable, Net of Deferred Income, Total	1,760,076	1,808,976
Real estate construction | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	0	1,618
Real estate construction | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	0	2
Real estate construction | 90+ Days Past Due
Summarized details of Loans
Total Past Due	0	0
Commercial real estate lending
Summarized details of Loans
Current	6,147,823	6,130,454
Nonaccrual(a)(b)	81,495	60,855
Loans and Leases Receivable, Net of Deferred Income, Total	6,229,317	6,193,545
Commercial real estate lending | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	0	1,759
Commercial real estate lending | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	0	477
Commercial real estate lending | 90+ Days Past Due
Summarized details of Loans
Total Past Due	0	0
Total commercial
Summarized details of Loans
Current	15,471,134	15,546,857
Nonaccrual(a)(b)	81,761	67,134
Loans and Leases Receivable, Net of Deferred Income, Total	15,554,303	15,617,256
Total commercial | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	1,121	2,541
Total commercial | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	163	573
Total commercial | 90+ Days Past Due
Summarized details of Loans
Total Past Due	125	151
Residential mortgage
Summarized details of Loans
Current	7,550,015	7,505,654
Nonaccrual(a)(b)	53,827	55,362
Loans and Leases Receivable, Net of Deferred Income, Total	7,609,343	7,567,310
Residential mortgage | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	4,867	5,500
Residential mortgage | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	90	669
Residential mortgage | 90+ Days Past Due
Summarized details of Loans
Total Past Due	544	126
Home equity
Summarized details of Loans
Current	569,170	584,177
Nonaccrual(a)(b)	7,490	7,726
Loans and Leases Receivable, Net of Deferred Income, Total	580,867	595,615
Home equity | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	3,632	2,867
Home equity | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	575	844
Home equity | 90+ Days Past Due
Summarized details of Loans
Total Past Due	0	0
Other consumer
Summarized details of Loans
Current	287,636	298,261
Nonaccrual(a)(b)	95	170
Loans and Leases Receivable, Net of Deferred Income, Total	289,889	301,723
Other consumer | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	707	1,835
Other consumer | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	525	472
Other consumer | 90+ Days Past Due
Summarized details of Loans
Total Past Due	926	986
Auto
Summarized details of Loans
Current	496,526	142,982
Nonaccrual(a)(b)	49	52
Loans and Leases Receivable, Net of Deferred Income, Total	497,523	143,045
Auto | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	906	11
Auto | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	42	0
Auto | 90+ Days Past Due
Summarized details of Loans
Total Past Due	0	0
Total consumer
Summarized details of Loans
Current	8,903,347	8,531,074
Nonaccrual(a)(b)	61,460	63,309
Loans and Leases Receivable, Net of Deferred Income, Total	8,977,622	8,607,693
Total consumer | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	10,112	10,213
Total consumer | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	1,232	1,985
Total consumer | 90+ Days Past Due
Summarized details of Loans
Total Past Due	$ 1,470	$ 1,111