Allowance for Credit Losses (Non-Accrual Loans and Leases and Loans and Leases Past Due) (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	$ 37,642,413	$ 37,441,951
Non-Accrual	98,696	74,371
Financing Receivable, Nonaccrual, No Allowance	4,666	4,901
Loans Insured or Guaranteed by US Government Authorities [Member]
Financing Receivable, Past Due [Line Items]
Non-Accrual	31,300	19,300
Greater than 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	94,500	40,014
60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	15,173	45,221
90 Days or More and Accruing (2)
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	44,902	39,542
90 Days or More and Accruing (2) | Loans Insured or Guaranteed by US Government Authorities [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	11,700	12,300
Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	154,575	124,777
Current and Other
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	37,389,142	37,242,803
Commercial real estate
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	19,631,173	19,454,480
Commercial real estate | Commercial Real Estate, Non-owner Occupied Term [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	6,557,768	6,482,940
Non-Accrual	5,382	4,359
Financing Receivable, Nonaccrual, No Allowance	37	52
Commercial real estate | Owner occupied term, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	5,231,676	5,195,605
Non-Accrual	34,354	24,330
Financing Receivable, Nonaccrual, No Allowance	1,492	1,352
Commercial real estate | Multifamily [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	5,828,960	5,704,734
Non-Accrual	0	0
Commercial real estate | Construction & development, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	1,728,652	1,747,302
Non-Accrual	0	0
Commercial real estate | Residential development, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	284,117	323,899
Non-Accrual	0	0
Commercial real estate | Greater than 30 to 59 Days Past Due | Commercial Real Estate, Non-owner Occupied Term [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	2,237	1,270
Commercial real estate | Greater than 30 to 59 Days Past Due | Owner occupied term, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	2,275	3,078
Commercial real estate | Greater than 30 to 59 Days Past Due | Multifamily [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	0	0
Commercial real estate | Greater than 30 to 59 Days Past Due | Construction & development, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	0	0
Commercial real estate | Greater than 30 to 59 Days Past Due | Residential development, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	0	0
Commercial real estate | 60 to 89 Days Past Due | Commercial Real Estate, Non-owner Occupied Term [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	517	3,312
Commercial real estate | 60 to 89 Days Past Due | Owner occupied term, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	245	2,191
Commercial real estate | 60 to 89 Days Past Due | Multifamily [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	0	0
Commercial real estate | 60 to 89 Days Past Due | Construction & development, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	0	0
Commercial real estate | 60 to 89 Days Past Due | Residential development, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	0	0
Commercial real estate | 90 Days or More and Accruing (2) | Commercial Real Estate, Non-owner Occupied Term [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	253	437
Commercial real estate | 90 Days or More and Accruing (2) | Owner occupied term, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	0	433
Commercial real estate | 90 Days or More and Accruing (2) | Multifamily [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	0	0
Commercial real estate | 90 Days or More and Accruing (2) | Construction & development, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	0	0
Commercial real estate | 90 Days or More and Accruing (2) | Residential development, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	0	0
Commercial real estate | Total Past Due | Commercial Real Estate, Non-owner Occupied Term [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	3,007	5,019
Commercial real estate | Total Past Due | Owner occupied term, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	2,520	5,702
Commercial real estate | Total Past Due | Multifamily [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	0	0
Commercial real estate | Total Past Due | Construction & development, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	0	0
Commercial real estate | Total Past Due | Residential development, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	0	0
Commercial real estate | Current and Other | Commercial Real Estate, Non-owner Occupied Term [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	6,549,379	6,473,562
Commercial real estate | Current and Other | Owner occupied term, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	5,194,802	5,165,573
Commercial real estate | Current and Other | Multifamily [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	5,828,960	5,704,734
Commercial real estate | Current and Other | Construction & development, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	1,728,652	1,747,302
Commercial real estate | Current and Other | Residential development, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	284,117	323,899
Commercial
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	9,742,766	9,696,404
Commercial | Term, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	5,544,450	5,536,765
Non-Accrual	26,032	14,519
Financing Receivable, Nonaccrual, No Allowance	3,137	3,497
Commercial | Lines of credit & other, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	2,491,557	2,430,127
Non-Accrual	2,335	2,760
Commercial | Leases & equipment finance, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	1,706,759	1,729,512
Non-Accrual	30,593	28,403
Commercial | Greater than 30 to 59 Days Past Due | Term, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	4,946	6,341
Commercial | Greater than 30 to 59 Days Past Due | Lines of credit & other, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	37,219	1,647
Commercial | Greater than 30 to 59 Days Past Due | Leases & equipment finance, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	26,837	22,217
Commercial | 60 to 89 Days Past Due | Term, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	1,493	2,101
Commercial | 60 to 89 Days Past Due | Lines of credit & other, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	1,736	1,137
Commercial | 60 to 89 Days Past Due | Leases & equipment finance, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	8,551	24,178
Commercial | 90 Days or More and Accruing (2) | Term, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	832	202
Commercial | 90 Days or More and Accruing (2) | Lines of credit & other, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	1,966	66
Commercial | 90 Days or More and Accruing (2) | Leases & equipment finance, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	7,935	7,965
Commercial | Total Past Due | Term, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	7,271	8,644
Commercial | Total Past Due | Lines of credit & other, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	40,921	2,850
Commercial | Total Past Due | Leases & equipment finance, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	43,323	54,360
Commercial | Current and Other | Term, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	5,511,147	5,513,602
Commercial | Current and Other | Lines of credit & other, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	2,448,301	2,424,517
Commercial | Current and Other | Leases & equipment finance, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	1,632,843	1,646,749
Residential
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	8,079,305	8,095,332
Residential | Mortgage, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	6,128,884	6,157,166
Non-Accrual	0	0
Residential | Home equity loans & lines, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	1,950,421	1,938,166
Non-Accrual	0	0
Residential | Greater than 30 to 59 Days Past Due | Mortgage, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	14,452	282
Residential | Greater than 30 to 59 Days Past Due | Home equity loans & lines, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	5,746	4,401
Residential | 60 to 89 Days Past Due | Mortgage, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	0	9,410
Residential | 60 to 89 Days Past Due | Home equity loans & lines, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	2,411	2,373
Residential | 90 Days or More and Accruing (2) | Mortgage, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	30,040	26,331
Residential | 90 Days or More and Accruing (2) | Mortgage, net | GNMA Loans
Financing Receivable, Past Due [Line Items]
GNMA Loans past due by 90 days, but not yet repurchased	1,600	1,000
Residential | 90 Days or More and Accruing (2) | Home equity loans & lines, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	3,439	3,782
Residential | Total Past Due | Mortgage, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	44,492	36,023
Residential | Total Past Due | Home equity loans & lines, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	11,596	10,556
Residential | Current and Other | Mortgage, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	6,084,392	6,121,143
Residential | Current and Other | Home equity loans & lines, net
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	1,938,825	1,927,610
Consumer Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	189,169	195,735
Non-Accrual	0	0
Consumer Portfolio Segment [Member] | Greater than 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	788	778
Consumer Portfolio Segment [Member] | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	220	519
Consumer Portfolio Segment [Member] | 90 Days or More and Accruing (2)
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	437	326
Consumer Portfolio Segment [Member] | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	1,445	1,623
Consumer Portfolio Segment [Member] | Current and Other
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	$ 187,724	$ 194,112