Loans Past Due Status (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Summarized details of Loans
Current	$ 29,058,504	$ 28,652,257
Financing Receivable, Nonaccrual	117,569	111,467
Loans and Leases Receivable, Net of Deferred Income, Total	29,207,072	28,799,569
Nonaccrual Loans, Current Portion	$ 78,000	$ 64,000
Percent of current nonaccrual loans	66.00%	58.00%
Financing Receivable, Nonaccrual, Interest Income	$ 0	$ 0
Financing Receivable, Nonaccrual, No Allowance	15,000	11,000
30-59 Days Past Due
Summarized details of Loans
Total Past Due	26,167	26,256
60-89 Days Past Due
Summarized details of Loans
Total Past Due	3,130	7,861
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Summarized details of Loans
Total Past Due	1,703	1,728
Asset-based lending & equipment finance
Summarized details of Loans
Current	522,834	458,887
Financing Receivable, Nonaccrual	0	0
Loans and Leases Receivable, Net of Deferred Income, Total	522,834	458,887
Asset-based lending & equipment finance | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	0	0
Asset-based lending & equipment finance | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	0	0
Asset-based lending & equipment finance | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Summarized details of Loans
Total Past Due	0	0
Commercial and Industrial Sector
Summarized details of Loans
Current	9,319,650	9,279,674
Financing Receivable, Nonaccrual	22,735	14,329
Loans and Leases Receivable, Net of Deferred Income, Total	9,346,947	9,300,567
Commercial and Industrial Sector | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	4,110	716
Commercial and Industrial Sector | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	130	5,566
Commercial and Industrial Sector | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Summarized details of Loans
Total Past Due	323	282
Commercial real estate — owner occupied
Summarized details of Loans
Current	1,045,803	991,493
Financing Receivable, Nonaccrual	1,478	0
Loans and Leases Receivable, Net of Deferred Income, Total	1,050,236	991,722
Commercial real estate — owner occupied | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	2,955	218
Commercial real estate — owner occupied | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	0	12
Commercial real estate — owner occupied | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Summarized details of Loans
Total Past Due	0	0
Commercial and business lending
Summarized details of Loans
Current	10,888,287	10,730,053
Financing Receivable, Nonaccrual	24,213	14,329
Loans and Leases Receivable, Net of Deferred Income, Total	10,920,017	10,751,176
Commercial and business lending | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	7,065	934
Commercial and business lending | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	130	5,578
Commercial and business lending | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Summarized details of Loans
Total Past Due	323	282
Commercial real estate — investor
Summarized details of Loans
Current	5,069,126	5,049,897
Financing Receivable, Nonaccrual	25,122	29,380
Loans and Leases Receivable, Net of Deferred Income, Total	5,094,249	5,080,344
Commercial real estate — investor | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	0	1,067
Commercial real estate — investor | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	0	0
Commercial real estate — investor | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Summarized details of Loans
Total Past Due	0	0
Real estate construction
Summarized details of Loans
Current	2,146,892	2,155,077
Financing Receivable, Nonaccrual	178	105
Loans and Leases Receivable, Net of Deferred Income, Total	2,147,070	2,155,222
Real estate construction | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	0	39
Real estate construction | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	0	0
Real estate construction | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Summarized details of Loans
Total Past Due	0	0
Commercial real estate lending
Summarized details of Loans
Current	7,216,018	7,204,975
Financing Receivable, Nonaccrual	25,300	29,485
Loans and Leases Receivable, Net of Deferred Income, Total	7,241,318	7,235,565
Commercial real estate lending | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	0	1,105
Commercial real estate lending | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	0	0
Commercial real estate lending | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Summarized details of Loans
Total Past Due	0	0
Total commercial
Summarized details of Loans
Current	18,104,305	17,935,028
Financing Receivable, Nonaccrual	49,513	43,814
Loans and Leases Receivable, Net of Deferred Income, Total	18,161,335	17,986,742
Total commercial | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	7,065	2,040
Total commercial | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	130	5,578
Total commercial | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Summarized details of Loans
Total Past Due	323	282
Residential mortgage
Summarized details of Loans
Current	8,539,264	8,443,072
Financing Receivable, Nonaccrual	58,274	58,480
Loans and Leases Receivable, Net of Deferred Income, Total	8,605,164	8,511,550
Residential mortgage | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	7,430	9,811
Residential mortgage | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	196	63
Residential mortgage | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Summarized details of Loans
Total Past Due	0	124
Auto finance
Summarized details of Loans
Current	1,540,463	1,371,176
Financing Receivable, Nonaccrual	2,436	1,490
Loans and Leases Receivable, Net of Deferred Income, Total	1,551,538	1,382,073
Auto finance | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	7,330	8,238
Auto finance | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	1,310	1,170
Auto finance | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Summarized details of Loans
Total Past Due	0	0
Home equity
Summarized details of Loans
Current	598,427	611,259
Financing Receivable, Nonaccrual	7,246	7,487
Loans and Leases Receivable, Net of Deferred Income, Total	609,787	624,353
Home equity | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	3,366	5,149
Home equity | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	747	458
Home equity | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Summarized details of Loans
Total Past Due	0	0
Other consumer
Summarized details of Loans
Current	276,045	291,722
Financing Receivable, Nonaccrual	100	197
Loans and Leases Receivable, Net of Deferred Income, Total	279,248	294,851
Other consumer | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	976	1,018
Other consumer | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	747	592
Other consumer | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Summarized details of Loans
Total Past Due	1,380	1,322
Total consumer
Summarized details of Loans
Current	10,954,199	10,717,229
Financing Receivable, Nonaccrual	68,056	67,654
Loans and Leases Receivable, Net of Deferred Income, Total	11,045,737	10,812,828
Total consumer | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	19,102	24,216
Total consumer | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	3,000	2,283
Total consumer | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Summarized details of Loans
Total Past Due	$ 1,380	$ 1,446