Employee Benefits (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
BOK Financial Pension Plan [Member] | Pension Plan [Member]
BOK Financial Pension Plan [Abstract]
Defined Benefit Plan, Plan Assets, Payment for Settlement	$ 15,500,000
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Assets Transferred to (from) Plan	$ (19,100,000)
Defined Benefit Plan, Benefit Obligation		$ 20,000,000
Net periodic benefit credit		(2,200,000)	$ (1,300,000)
BOK Financial Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Nonrecurring [Member] | Pension Plan [Member]
BOK Financial Pension Plan [Abstract]
Defined Benefit Plan, Plan Assets, Amount		39,000,000
BOK Financial 401(k) Plan [Member]
BOK Financial 401(k) Plan [Abstract]
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	6.00%
Defined Contribution Plan, Minimum Years of Service for Employees to Obtain Maximum Employer Matching	4 years
Defined Contribution Plan, Maximum Years of Service for Employees to Obtain Minimum Employer Matching	15 years
Defined Contribution Plan, Additional Annual Employer Matching Contribution, Percent	5.00%
Contributions Non-Elective Annual Contributions For Qualified Employees	$ 750
Defined Contribution Plan, Annual Base Employee Compensation to Qualify for Non-Elective Employer Contributions, Maximum	$ 40,000
Defined Contribution Plan, Vesting Period for Employer Contributions	5 years
Defined Contribution Plan, Cost	$ 31,700,000	$ 30,500,000	$ 29,900,000
BOK Financial 401(k) Plan [Member] | Minimum [Member]
BOK Financial 401(k) Plan [Abstract]
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	50.00%
BOK Financial 401(k) Plan [Member] | Maximum [Member]
BOK Financial 401(k) Plan [Abstract]
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	200.00%