Loans and Allowance for Credit Losses (Schedule of Financing Receivables Past Due) (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Financing Receivable Investment Past Due [Line Items]
Loans	$ 23,702,494	$ 24,297,980
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable Investment Past Due [Line Items]
Loans	6,534,615	6,214,192
Commercial and Industrial Portfolio Segment [Member]
Financing Receivable Investment Past Due [Line Items]
Loans	8,555,869	8,983,226
Pinnacle - municipal finance
Financing Receivable Investment Past Due [Line Items]
Loans	637,198	720,661
Franchise and equipment finance
Financing Receivable Investment Past Due [Line Items]
Loans	134,635	213,477
Mortgage warehouse lending
Financing Receivable Investment Past Due [Line Items]
Loans	709,185	585,610
1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Loans	6,199,657	6,508,922
US Government Agency Insured Loans [Member]
Financing Receivable Investment Past Due [Line Items]
Loans	931,335	1,071,892
Current
Financing Receivable Investment Past Due [Line Items]
Loans	23,161,469	23,720,130
Current \| Commercial Real Estate Portfolio Segment [Member]
Financing Receivable Investment Past Due [Line Items]
Loans	6,460,963	6,145,386
Current \| Commercial and Industrial Portfolio Segment [Member]
Financing Receivable Investment Past Due [Line Items]
Loans	8,438,213	8,911,057
Current \| Pinnacle - municipal finance
Financing Receivable Investment Past Due [Line Items]
Loans	637,198	720,661
Current \| Franchise and equipment finance
Financing Receivable Investment Past Due [Line Items]
Loans	134,635	213,477
Current \| Mortgage warehouse lending
Financing Receivable Investment Past Due [Line Items]
Loans	709,185	585,610
Current \| 1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Loans	6,144,662	6,452,828
Current \| US Government Agency Insured Loans [Member]
Financing Receivable Investment Past Due [Line Items]
Loans	636,613	691,111
30 - 59 Days Past Due
Financing Receivable Investment Past Due [Line Items]
Loans	170,724	192,399
30 - 59 Days Past Due \| Commercial Real Estate Portfolio Segment [Member]
Financing Receivable Investment Past Due [Line Items]
Loans	10,000	35,000
30 - 59 Days Past Due \| Commercial and Industrial Portfolio Segment [Member]
Financing Receivable Investment Past Due [Line Items]
Loans	33,737	16,137
30 - 59 Days Past Due \| Pinnacle - municipal finance
Financing Receivable Investment Past Due [Line Items]
Loans	0	0
30 - 59 Days Past Due \| Franchise and equipment finance
Financing Receivable Investment Past Due [Line Items]
Loans	0	0
30 - 59 Days Past Due \| Mortgage warehouse lending
Financing Receivable Investment Past Due [Line Items]
Loans	0	0
30 - 59 Days Past Due \| 1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Loans	32,995	32,975
30 - 59 Days Past Due \| US Government Agency Insured Loans [Member]
Financing Receivable Investment Past Due [Line Items]
Loans	93,992	108,287
60 - 89 Days Past Due
Financing Receivable Investment Past Due [Line Items]
Loans	81,637	78,481
60 - 89 Days Past Due \| Commercial Real Estate Portfolio Segment [Member]
Financing Receivable Investment Past Due [Line Items]
Loans	1,344	0
60 - 89 Days Past Due \| Commercial and Industrial Portfolio Segment [Member]
Financing Receivable Investment Past Due [Line Items]
Loans	35,242	25,645
60 - 89 Days Past Due \| Pinnacle - municipal finance
Financing Receivable Investment Past Due [Line Items]
Loans	0	0
60 - 89 Days Past Due \| Franchise and equipment finance
Financing Receivable Investment Past Due [Line Items]
Loans	0	0
60 - 89 Days Past Due \| Mortgage warehouse lending
Financing Receivable Investment Past Due [Line Items]
Loans	0	0
60 - 89 Days Past Due \| 1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Loans	7,028	6,155
60 - 89 Days Past Due \| US Government Agency Insured Loans [Member]
Financing Receivable Investment Past Due [Line Items]
Loans	38,023	46,681
90 Days or More Past Due
Financing Receivable Investment Past Due [Line Items]
Loans	288,664	306,970
90 Days or More Past Due \| Commercial Real Estate Portfolio Segment [Member]
Financing Receivable Investment Past Due [Line Items]
Loans	62,308	33,806
90 Days or More Past Due \| Commercial and Industrial Portfolio Segment [Member]
Financing Receivable Investment Past Due [Line Items]
Loans	48,677	30,387
90 Days or More Past Due \| Pinnacle - municipal finance
Financing Receivable Investment Past Due [Line Items]
Loans	0	0
90 Days or More Past Due \| Franchise and equipment finance
Financing Receivable Investment Past Due [Line Items]
Loans	0	0
90 Days or More Past Due \| Mortgage warehouse lending
Financing Receivable Investment Past Due [Line Items]
Loans	0	0
90 Days or More Past Due \| 1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Loans	14,972	16,964
90 Days or More Past Due \| US Government Agency Insured Loans [Member]
Financing Receivable Investment Past Due [Line Items]
Loans	$ 162,707	$ 225,813