Percentage, before allowance for credit loss, of financing receivable to total financing receivable.

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Loans and Allowance for Credit Losses (Schedule of Loans) (Details) - USD ($) $ in Thousands	Sep. 30, 2026	Jun. 30, 2026	Dec. 31, 2025	Sep. 30, 2025	Jun. 30, 2025	Dec. 31, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 23,815,356		$ 24,273,707
Allowance for credit losses	(221,476)	$ (217,516)	(219,825)	$ (219,884)	$ (222,730)	$ (223,153)
Loans, net	$ 23,593,880		$ 24,053,882
Percent of Total Loans	100.00%		100.00%
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 17,229,459		$ 17,290,707
Allowance for credit losses	$ (208,865)	(205,141)	$ (208,412)	(206,712)	(208,961)	(211,203)
Percent of Total Loans	72.40%		71.20%
Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 6,585,897		$ 6,983,000
Allowance for credit losses	$ (12,611)	$ (12,375)	$ (11,413)	$ (13,172)	$ (13,769)	$ (11,950)
Percent of Total Loans	27.60%		28.80%
Non-owner occupied commercial real estate \| Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 6,445,359		$ 6,105,207
Percent of Total Loans	27.20%		25.20%
Construction and land \| Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 628,015		$ 705,664
Percent of Total Loans	2.60%		2.90%
Owner occupied commercial real estate \| Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 2,114,989		$ 2,020,572
Percent of Total Loans	8.90%		8.30%
Commercial and industrial \| Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 6,457,171		$ 7,008,903
Percent of Total Loans	27.10%		28.80%
Pinnacle - municipal finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 592,293		$ 619,374
Pinnacle - municipal finance \| Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 592,293		$ 619,374
Percent of Total Loans	2.50%		2.60%
Franchise and equipment finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 59,342		$ 102,746
Franchise and equipment finance \| Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 59,342		$ 102,746
Percent of Total Loans	0.20%		0.40%
Mortgage warehouse lending
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 932,290		$ 728,241
Mortgage warehouse lending \| Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 932,290		$ 728,241
Percent of Total Loans	3.90%		3.00%
1-4 single family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 5,774,390		$ 6,091,959
1-4 single family residential \| Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 5,774,390		$ 6,091,959
Percent of Total Loans	24.20%		25.10%
Government insured residential \| Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 811,507		$ 891,041
Percent of Total Loans	3.40%		3.70%