Commitments and Contingent Liabilities (Details) $ in Millions	Jun. 30, 2016 USD ($) shares
Parent Company [Member] | Visa Membership [Member]
Loss Contingencies [Line Items]
Number of Visa Class B Shares Owned by Entity (in shares)	251,837
Number of Visa Class A Shares Visa Class B Shares Are Convertible To (in shares)	415,103
BOKF Equity, LLC [Member]
Loss Contingencies [Line Items]
Number of Private Equity Funds of which the Entity is a General Partner	2
Contingent Obligations For Additional Investments in Private Equity Funds | $	$ 4.5
Cavanal Hill Funds [Member]
Loss Contingencies [Line Items]
The Net Asset Value of Units in Mutual Funds (per unit)	1.00