Commitments and Contingent Liabilities (Details) (USD $)	12 Months Ended			0 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Oct. 11, 2011 BOKF, NA [Member] Invalidated Settlement by Oklahoma Supreme Court [Member]	Dec. 31, 2012 BOKF, NA [Member] Invalidated Settlement by Oklahoma Supreme Court [Member]	Dec. 31, 2013 Parent Company [Member] Visa Membership [Member]	Dec. 31, 2013 Cavanal Hill Funds [Member]	Dec. 31, 2013 BOKF Equity, LLC [Member]
Loss Contingencies [Line Items]
Settlement Agreement, Counterparty's Name				City of Tulsa
Settlement Agreement, Amount					$ 7,100,000
Number of Visa Class B Shares Owned by Entity (in shares)						251,837
Amount Deposited by Visa in Escrow for Covered Litigation						150,000,000
Current Exchange Rate For Class A shares For Each Class B Share						0.4206
Number of Private Equity Funds of which the Entity is a General Partner	2
Contingent Obligations For Additional Investments in Private Equity Funds								5,900,000
Mutual Fund Investment in US Treasury Securities							884,000,000
Mutual Fund Investment in Cash Management							1,200,000,000
Mutual Fund Investment in Tax-Free Money Market Funds							314,000,000
The Net Asset Value of Units in Mutual Funds (per unit)							1.00
Operating Leases, Rent Expense, Net	23,500,000	21,700,000	20,600,000
Operating Leases, Future Minimum Payments Due, Next Twelve Months	23,800,000
Operating Leases, Future Minimum Payments, Due in Two Years	23,900,000
Operating Leases, Future Minimum Payments, Due in Three Years	21,500,000
Operating Leases, Future Minimum Payments, Due in Four Years	17,900,000
Operating Leases, Future Minimum Payments, Due in Five Years	13,800,000
Operating Leases, Future Minimum Payments, Due Thereafter	113,000,000
Minimum Average Cash Balance Required to be Maintained at Federal Reserve by Subsidiary Bank	$ 830,000,000	$ 733,000,000