Loans and Allowance for Credit Losses (Schedule of Financing Receivables Past Due) (Details) - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025
Financing Receivable Investment Past Due [Line Items]
Loans	$ 23,815,356	$ 24,273,707
CRE
Financing Receivable Investment Past Due [Line Items]
Loans	7,073,374	6,810,871
C&I
Financing Receivable Investment Past Due [Line Items]
Loans	8,572,160	9,029,475
Pinnacle - municipal finance
Financing Receivable Investment Past Due [Line Items]
Loans	592,293	619,374
Franchise and equipment finance
Financing Receivable Investment Past Due [Line Items]
Loans	59,342	102,746
Mortgage warehouse lending
Financing Receivable Investment Past Due [Line Items]
Loans	932,290	728,241
1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Loans	5,774,390	6,091,959
Government insured residential
Financing Receivable Investment Past Due [Line Items]
Loans	811,507	891,041
Current
Financing Receivable Investment Past Due [Line Items]
Loans	23,350,932	23,738,618
Current \| CRE
Financing Receivable Investment Past Due [Line Items]
Loans	7,046,035	6,768,897
Current \| C&I
Financing Receivable Investment Past Due [Line Items]
Loans	8,469,510	8,893,254
Current \| Pinnacle - municipal finance
Financing Receivable Investment Past Due [Line Items]
Loans	592,293	619,374
Current \| Franchise and equipment finance
Financing Receivable Investment Past Due [Line Items]
Loans	59,342	102,746
Current \| Mortgage warehouse lending
Financing Receivable Investment Past Due [Line Items]
Loans	932,290	728,241
Current \| 1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Loans	5,709,156	6,021,772
Current \| Government insured residential
Financing Receivable Investment Past Due [Line Items]
Loans	542,306	604,334
30 - 59 Days Past Due
Financing Receivable Investment Past Due [Line Items]
Loans	135,562	156,658
30 - 59 Days Past Due \| CRE
Financing Receivable Investment Past Due [Line Items]
Loans	0	751
30 - 59 Days Past Due \| C&I
Financing Receivable Investment Past Due [Line Items]
Loans	16,148	6,136
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	42,472	48,099
30 - 59 Days Past Due \| Government insured residential
Financing Receivable Investment Past Due [Line Items]
Loans	76,942	101,672
60 - 89 Days Past Due
Financing Receivable Investment Past Due [Line Items]
Loans	53,926	93,972
60 - 89 Days Past Due \| CRE
Financing Receivable Investment Past Due [Line Items]
Loans	21,321	14,867
60 - 89 Days Past Due \| C&I
Financing Receivable Investment Past Due [Line Items]
Loans	5,359	48,711
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	5,757	4,468
60 - 89 Days Past Due \| Government insured residential
Financing Receivable Investment Past Due [Line Items]
Loans	21,489	25,926
90 Days or More Past Due
Financing Receivable Investment Past Due [Line Items]
Loans	274,936	284,459
90 Days or More Past Due \| CRE
Financing Receivable Investment Past Due [Line Items]
Loans	6,018	26,356
90 Days or More Past Due \| C&I
Financing Receivable Investment Past Due [Line Items]
Loans	81,143	81,374
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	17,005	17,620
90 Days or More Past Due \| Government insured residential
Financing Receivable Investment Past Due [Line Items]
Loans	$ 170,770	$ 159,109