Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2017

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Activity Under Stock Option Plan

The following table is a summary of the activity under both the BancFirst ISOP and the BancFirst Directors’ Stock Option Plan:

						Wgtd. Avg.
				Wgtd. Avg.		Remaining	Aggregate
				Exercise		Contractual	Intrinsic
	Options			Price		Term	Value
	(Dollars in thousands, except option data)
Year Ended December 31, 2017
Outstanding at December 31, 2016		1,414,900		$	22.46
Options granted		121,500			48.26
Options exercised		(262,775	)		17.73
Outstanding at December 31, 2017		1,273,625			25.90	9.73Yrs	$	32,165
Exercisable at December 31, 2017		566,625			20.07	6.92Yrs	$	17,611
Year Ended December 31, 2016
Outstanding at December 31, 2015		2,036,298		$	20.35
Options granted		60,000			29.04
Options exercised		(621,398	)		15.64
Options canceled, forfeited, or expired		(60,000	)		27.94
Outstanding at December 31, 2016		1,414,900			22.46	9.59Yrs	$	34,049
Exercisable at December 31, 2016		650,400			18.60	6.78Yrs	$	18,167

Options Granted and Options Exercised Under Stock Option Plan

The following table has additional information regarding options granted and options exercised under both the BancFirst ISOP and the BancFirst Directors’ Stock Option Plan:

	Year Ended December 31,
	2017		2016		2015
	(Dollars in thousands, except per share data)
Weighted average grant-date fair value per share of options granted	$	11.87	$	5.96	$	5.86
Total intrinsic value of options exercised		8,389		12,230		4,376
Cash received from options exercised		4,660		9,720		3,212
Tax benefit realized from options exercised		3,245		4,731		1,693

Stock-based Employee Compensation Expense

The following table is a summary of the Company’s recorded stock-based compensation expense:

	Year Ended December 31,
	2017		2016		2015
	(Dollars in thousands)
Stock-based compensation expense	$	1,180	$	1,636	$	1,717
Tax benefit		301		633		664
Stock-based compensation expense, net of tax	$	879	$	1,003	$	1,053

Unearned Stock-based Compensation Expense

The Company will continue to amortize the unearned stock-based compensation expense over the remaining vesting period of approximately seven years. The following table shows the unearned stock-based compensation expense:

	December 31, 2017
	(Dollars in thousands)
Unearned stock-based compensation expense	$	3,268

Assumptions Used for Computing Stock-Based Compensation Expense

The following table shows the assumptions used for computing stock-based compensation expense under the fair value method on options granted during the periods presented:

Year Ended December 31,

2017

2016

2015

Risk-free interest rate

2.15 to 2.40%

1.46 to 2.02%

1.83 to 2.26%

Dividend yield

2.00

Stock price volatility

22.57 to 24.18%

20.41 to 21.78%

18.23 to 21.08%

Expected term

10 Yrs

Summary of Accumulated Stock Units

A summary of the accumulated stock units is as follows:

	December 31,
	2017		2016
Accumulated stock units		138,768		140,044
Average price	$	22.84	$	20.87