Loans Past Due Status (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2023	Dec. 31, 2022
Summarized details of Loans
Current	$ 29,675,892	$ 29,675,892	$ 28,652,257
Financing Receivable, Nonaccrual	131,278	131,278	111,467
Loans and Leases Receivable, Net of Deferred Income, Total	29,848,904	29,848,904	28,799,569
Nonaccrual Loans, Current Portion	$ 77,000	$ 77,000	$ 64,000
Percent of current nonaccrual loans	58.00%	58.00%	58.00%
Financing Receivable, Nonaccrual, Interest Income	$ 0	$ 0	$ 0
Financing Receivable, Nonaccrual, No Allowance	29,000	29,000	11,000
30-59 Days Past Due
Summarized details of Loans
Total Past Due	36,585	36,585	26,256
60-89 Days Past Due
Summarized details of Loans
Total Past Due	3,423	3,423	7,861
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Summarized details of Loans
Total Past Due	1,726	1,726	1,728
Commercial and Industrial Sector
Summarized details of Loans
Current	10,008,208	10,008,208	9,738,561
Financing Receivable, Nonaccrual	34,907	34,907	14,329
Loans and Leases Receivable, Net of Deferred Income, Total	10,055,487	10,055,487	9,759,454
Commercial and Industrial Sector | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	11,837	11,837	716
Commercial and Industrial Sector | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	168	168	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	366	366	282
Commercial real estate — owner occupied
Summarized details of Loans
Current	1,055,309	1,055,309	991,493
Financing Receivable, Nonaccrual	1,444	1,444	0
Loans and Leases Receivable, Net of Deferred Income, Total	1,058,237	1,058,237	991,722
Commercial real estate — owner occupied | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	1,484	1,484	218
Commercial real estate — owner occupied | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	0	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	0
Commercial and business lending
Summarized details of Loans
Current	11,063,517	11,063,517	10,730,053
Financing Receivable, Nonaccrual	36,352	36,352	14,329
Loans and Leases Receivable, Net of Deferred Income, Total	11,113,724	11,113,724	10,751,176
Commercial and business lending | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	13,321	13,321	934
Commercial and business lending | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	168	168	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	366	366	282
Commercial real estate — investor
Summarized details of Loans
Current	5,290,860	5,290,860	5,049,897
Financing Receivable, Nonaccrual	22,068	22,068	29,380
Loans and Leases Receivable, Net of Deferred Income, Total	5,312,928	5,312,928	5,080,344
Commercial real estate — investor | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	0	0	1,067
Commercial real estate — investor | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	0	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	0
Real estate construction
Summarized details of Loans
Current	2,008,859	2,008,859	2,155,077
Financing Receivable, Nonaccrual	125	125	105
Loans and Leases Receivable, Net of Deferred Income, Total	2,009,060	2,009,060	2,155,222
Real estate construction | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	76	76	39
Real estate construction | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	0	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	0
Commercial real estate lending
Summarized details of Loans
Current	7,299,719	7,299,719	7,204,975
Financing Receivable, Nonaccrual	22,193	22,193	29,485
Loans and Leases Receivable, Net of Deferred Income, Total	7,321,988	7,321,988	7,235,565
Commercial real estate lending | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	76	76	1,105
Commercial real estate lending | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	0	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	0
Total commercial
Summarized details of Loans
Current	18,363,236	18,363,236	17,935,028
Financing Receivable, Nonaccrual	58,544	58,544	43,814
Loans and Leases Receivable, Net of Deferred Income, Total	18,435,711	18,435,711	17,986,742
Total commercial | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	13,396	13,396	2,040
Total commercial | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	168	168	5,578
Total commercial | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Summarized details of Loans
Total Past Due	366	366	282
Residential mortgage
Summarized details of Loans
Current	8,675,666	8,675,666	8,443,072
Financing Receivable, Nonaccrual	61,718	61,718	58,480
Loans and Leases Receivable, Net of Deferred Income, Total	8,746,345	8,746,345	8,511,550
Residential mortgage | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	8,791	8,791	9,811
Residential mortgage | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	170	170	63
Residential mortgage | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Summarized details of Loans
Total Past Due	0	0	124
Auto finance
Summarized details of Loans
Current	1,763,481	1,763,481	1,371,176
Financing Receivable, Nonaccrual	3,065	3,065	1,490
Loans and Leases Receivable, Net of Deferred Income, Total	1,777,974	1,777,974	1,382,073
Auto finance | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	9,833	9,833	8,238
Auto finance | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	1,596	1,596	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	0
Home equity
Summarized details of Loans
Current	603,688	603,688	611,259
Financing Receivable, Nonaccrual	7,788	7,788	7,487
Loans and Leases Receivable, Net of Deferred Income, Total	615,506	615,506	624,353
Home equity | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	3,286	3,286	5,149
Home equity | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	744	744	458
Home equity | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Summarized details of Loans
Total Past Due	0	0	0
Other consumer
Summarized details of Loans
Current	269,820	269,820	291,722
Financing Receivable, Nonaccrual	163	163	197
Loans and Leases Receivable, Net of Deferred Income, Total	273,367	273,367	294,851
Other consumer | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	1,279	1,279	1,018
Other consumer | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	745	745	592
Other consumer | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Summarized details of Loans
Total Past Due	1,360	1,360	1,322
Total consumer
Summarized details of Loans
Current	11,312,656	11,312,656	10,717,229
Financing Receivable, Nonaccrual	72,733	72,733	67,654
Loans and Leases Receivable, Net of Deferred Income, Total	11,413,193	11,413,193	10,812,828
Total consumer | 30-59 Days Past Due
Summarized details of Loans
Total Past Due	23,189	23,189	24,216
Total consumer | 60-89 Days Past Due
Summarized details of Loans
Total Past Due	3,255	3,255	2,283
Total consumer | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Summarized details of Loans
Total Past Due	$ 1,360	$ 1,360	$ 1,446