Commitments and Contingent Liabilities Variable Interest Entities (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Loans [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	$ 10,000,000	$ 10,000,000
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	18,192,000	27,319,000
Other Assets VIE [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	44,450,000	49,967,000
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	106,192,000	99,517,000
Other Liabilities VIE [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	32,970,000	37,457,000
Other Borrowings VIE [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	10,964,000	10,964,000
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Non-controlling Interest [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	34,027,000	34,924,000
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Private equity funds [Member] | Loans [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Private equity funds [Member] | Other Assets VIE [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	25,627,000	27,341,000
Private equity funds [Member] | Other Liabilities VIE [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Private equity funds [Member] | Other Borrowings VIE [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Private equity funds [Member] | Non-controlling Interest [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	21,921,000	23,036,000
Tax credit entities [Member] | Loans [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	10,000,000	10,000,000
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	18,192,000	27,319,000
Tax credit entities [Member] | Other Assets VIE [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	12,827,000	13,448,000
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	96,721,000	90,260,000
Tax credit entities [Member] | Other Liabilities VIE [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	28,920,000	35,776,000
Tax credit entities [Member] | Other Borrowings VIE [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	10,964,000	10,964,000
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Tax credit entities [Member] | Non-controlling Interest [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	10,000,000	9,869,000
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Other [Member] | Loans [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Other [Member] | Other Assets VIE [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	5,996,000	9,178,000
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	9,471,000	9,257,000
Other [Member] | Other Liabilities VIE [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	4,050,000	1,681,000
Other [Member] | Other Borrowings VIE [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Other [Member] | Non-controlling Interest [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	2,106,000	2,019,000
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	0	0
BOKF Equity, LLC [Member]
Variable Interest Entity [Line Items]
Number of Private Equity Funds of which the Entity is a General Partner	2
Contingent Obligation For Additional Investments In Private Equity Funds	$ 5,600,000