Junior Subordinated Debentures - Additional Information (Detail) (USD $)			12 Months Ended		0 Months Ended		12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Bancfirst Capital Trust Two [Member]	Dec. 31, 2013 Bancfirst Capital Trust Two [Member] Subordinated Debentures Subject to Mandatory Redemption [Member]	Mar. 31, 2004 Bancfirst Capital Trust Two [Member] Cumulative preferred stock [Member]	Feb. 29, 2004 Bancfirst Capital Trust Two [Member] Cumulative preferred stock [Member]	Dec. 31, 2013 Bancfirst Capital Trust Two [Member] Cumulative preferred stock [Member]
Junior Subordinated Debentures [Line Items]
Issue of securities					$ 1,000,000	$ 25,000,000
Cumulative trust preferred securities interest rate							7.20%
Interest rate of securities				7.20%
Frequency of payment				Payable January 15, April 15, July 15 and October 15 of each year
Junior Subordinated Notes Assumed	$ 26,804,000	$ 26,804,000		$ 26,800,000
Debt instrument maturity date			Mar. 31, 2034