XML 58 R48.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Acquisition Acquisitions (Details) - USD ($) shares in Millions, $ in Millions |  | 3 Months Ended
--- | --- | ---
Oct. 01, 2018 | Sep. 30, 2018
Cobiz Financial Inc. [Member] |  |
Business Acquisition [Line Items] |  |
Cobiz Financial Loans |  | $ 3,100.0
Cobiz Financial Assets |  | 3,900.0
Cobiz Financial Deposits |  | 3,300.0
Cobiz Financial Equity |  | $ 339.0
Switchgrass Holdings LLC [Member] |  |
Business Acquisition [Line Items] |  |
Business Acquisition, Effective Date of Acquisition |  | May 01, 2018
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Consideration Transferred |  | $ 14.0
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles |  | $ 6.7
Subsequent Event [Member] | Cobiz Financial Inc. [Member] |  |
Business Acquisition [Line Items] |  |
Business Acquisition, Effective Date of Acquisition | Oct. 01, 2018 |
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Consideration Transferred | $ 944.0 |
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Cash Paid | $ 242.0 |
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Shares Issued as Consideration | 7.2 |
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Share Value Transferred | $ 702.0 |

X
- Definition Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Cash Paid + References No definition available. + Details
Name: | bokf_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentCashPaid
Namespace Prefix: | bokf_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Share Value Transferred + References No definition available. + Details
Name: | bokf_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentShareValueTransferred
Namespace Prefix: | bokf_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Shares Issued as Consideration + References No definition available. + Details
Name: | bokf_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentSharesIssuedasConsideration
Namespace Prefix: | bokf_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Cobiz Financial Assets + References No definition available. + Details
Name: | bokf_CobizFinancialAssets
Namespace Prefix: | bokf_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Cobiz Financial Deposits + References No definition available. + Details
Name: | bokf_CobizFinancialDeposits
Namespace Prefix: | bokf_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Cobiz Financial Equity + References No definition available. + Details
Name: | bokf_CobizFinancialEquity
Namespace Prefix: | bokf_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Cobiz Financial Loans + References No definition available. + Details
Name: | bokf_CobizFinancialLoans
Namespace Prefix: | bokf_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Date when the acquirer obtains control of the acquiree, in CCYY-MM-DD format. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 25 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=84229725&loc=d3e848-128460 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 25 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=84229725&loc=d3e845-128460 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463 + Details
Name: | us-gaap_BusinessAcquisitionEffectiveDateOfAcquisition1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_BusinessAcquisitionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to items of consideration transferred in connection with a business combination for which the initial accounting was incomplete. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 4A -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84161108&loc=SL65897772-128472 + Details
Name: | us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentConsiderationTransferred
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to intangibles acquired in connection with a business combination for which the initial accounting was incomplete. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 4A -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84161108&loc=SL65897772-128472 + Details
Name: | us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentIntangibles
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=bokf_CobizFinancialInc.Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=bokf_SwitchgrassHoldingsLLCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |