Combined tier one and tier two ratio.

No definition available.

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- Definition

Common equity tier one risk based capital to risk weighted assets.

+ References

No definition available.

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- Definition

Implementation of deductions and other adjustments to CET one.

+ References

No definition available.

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- Definition

Implementation of deductions and other adjustments to CET one additional Percentage.

+ References

No definition available.

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- Definition

Implementation of deductions and other adjustments to CET one percentage.

+ References

No definition available.

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- Definition

Quantitative limit for trust preferred securities to be included in tier one capital.

+ References

No definition available.

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- Definition

Tier one capital conservation buffer maximum level.

+ References

No definition available.

+ Details

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- Definition

Tier one capital conservation buffer to risk weighted assets required under regulatory.

+ References

No definition available.

+ Details

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- Definition

Tier one risk based capital conservation buffer initial requirements phasing duration.

+ References

No definition available.

+ Details

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- Definition

Total Capital divided by risk weighted assets as defined in the regulations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 505

-Section 50

-Paragraph 1H

-Subparagraph (c)(2)

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 505

-Section 50

-Paragraph 1

-Subparagraph (c)(1)

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- Definition

The percentage rate used to calculate dividend payments on preferred stock.

+ References

No definition available.

+ Details

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- Definition

The price per share at which the preferred stock of an entity that has priority over common stock in the distribution of dividends and in the event of liquidation of the entity is redeemed or may be called at. The redemption features of this preferred stock are solely within the control of the issuer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 11

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-Topic 505

-SubTopic 10

-Section 50

-Paragraph 5

-Subparagraph (a)

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- Definition

Total number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) issued to shareholders (includes related preferred shares that were issued, repurchased, and remain in the treasury). May be all or portion of the number of preferred shares authorized. Excludes preferred shares that are classified as debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.28)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 29

-Article 5

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- Definition

Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased.

+ References

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- Definition

Amount of dividends that can be declared or paid without approval of regulatory agency.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(e))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph e

-Article 4

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- Definition

The amount of Tier 1 Leverage Capital required to be categorized as well capitalized divided by average assets as defined in the regulatory framework for prompt corrective action.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 505

-Section 50

-Paragraph 1

-Subparagraph (c)(1)

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- Definition

Tier 1 Leverage Capital divided by average assets as defined in the regulations.

+ References

+ Details

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- Definition

The Tier 1 capital ratio (Tier 1 capital divided by risk weighted assets) required to be categorized as "well capitalized" under the regulatory framework for prompt corrective action.

+ References

+ Details

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- Definition

Tier 1 capital divided by risk weighted assets as defined by regulations.

+ References

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Stockholders' Equity - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Jan. 01, 2015	Dec. 31, 2013
Stockholders Equity [Line Items]
Minimum Tier 1 Ratio to be well capitalized	6.00%
Minimum combined Tier 1 and Tier 2 Ratio to be well capitalized	10.00%banf_CombinedTierOneAndTierTwoRatio
Minimum Leverage Ratio to be well capitalized	5.00%
2015 [Member]
Stockholders Equity [Line Items]
Implementation of the deductions and other adjustments to CET1	4 years
Implementation of the deductions and other adjustments to CET1, Percentage	40.00%
After 2015 [Member]
Stockholders Equity [Line Items]
Implementation of the deductions and other adjustments to CET1, Additional Percentage	20.00%
2016 [Member]
Stockholders Equity [Line Items]
Implementation of the capital conservation buffer, Percentage	0.625%
Capital conservation buffer implementation phase-out period	4 years
2019 [Member]
Stockholders Equity [Line Items]
Capital Conservation Buffer Maximum Level	2.50%
Maximum [Member]
Stockholders Equity [Line Items]
Quantitative limit for trust preferred securities to be included in tier 1 capital	10,000,000,000
Minimum [Member] \| 2015 [Member]
Stockholders Equity [Line Items]
Minimum ratio of CET1 to risk-weighted assets	4.50%
Tier 1 capital to risk-weighted assets	6.00%
Total capital to risk weighted assets	8.00%
Minimum leverage ratio	4.00%
Subsequent Event [Member]
Stockholders Equity [Line Items]
Available equity of BancFirst for dividend payments to the company		$ 73,400,000
Senior Preferred Stock [Member]
Stockholders Equity [Line Items]
Preferred stock, shares issued	0		0
Preferred stock, shares outstanding	0
Cumulative Preferred Stock [Member]
Stockholders Equity [Line Items]
Preferred stock, shares issued	0		0
Preferred stock, shares outstanding	0
Dividend payable at redemption, per share	5.00
Cumulative preferred stock dividend rate	10.00%