Related Parties Related Parties (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Directors and Senior Management [Member]
Loans and Leases Receivable, Related Parties [Roll Forward]
Beginning balance		$ 204,409	$ 54,479
Advances		1,110,043	1,424,041
Payments		(1,131,474)	(1,281,323)
Adjustments	[1]	(1,330)	(7,212)
Ending balance		181,648	204,409	$ 54,479
Director [Member]
Loan Commitments and Equity Investments [Abstract]
Operating Costs and Expenses		$ 11,500	11,400	$ 10,700
Executive Officer [Member]
Loan Commitments and Equity Investments [Abstract]
Percentage of investment funds' assets held by clients		81.00%
Assets Held in Cavanal Hill Funds		$ 5,200,000
Subsidiaries [Member] | BOKF, NA [Member] | Affiliated Entity [Member]
Loan Commitments and Equity Investments [Abstract]
Maximum percentage of unimpaired capital on loan commitments and equity investments to a single affiliate (in hundredths)		10.00%
Maximum percentage of unimpaired capital on loan commitments and equity investments to all affiliates (in hundredths)		20.00%
Maximum loan commitments and equity investments to a single affiliate		$ 500,000
Maximum loan commitments and equity investments to all affiliates		1,000,000
Largest loan commitment and equity investment to a single affiliate		155,000
Aggregate loan commitment and equity investment to all affiliates		215,000	315,000
Largest amount outstanding to a single affiliate		408
Outstanding Receivables to all Affiliates		$ 408	$ 1,100

[1] Adjustments generally consist of changes in status as a related party.