Common Stock Plans (Tables)

12 Months Ended

Dec. 31, 2015

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Performance Share Award Activity

A summary of performance share award activity as of December 31, 2015, and transactions during the years ended December 31, 2015, 2014 and 2013 is presented below:

	Stock Incentive Plan
	Shares		Weighted Average Price
Nonvested at December 31, 2012	—		$	—
Granted (two-year vesting period)	86,221		61.14
Granted (three-year vesting period)	82,606		62.96
Forfeited	(8,008	)	60.03
Nonvested at December 31, 2013	160,819		62.13
Granted (two-year vesting period)	937		131.56
Granted (three-year vesting period)	65,309		93.49
Vested and paid	(14,097	)	70.06
Nonvested at December 31, 2014	212,968		71.53
Granted (three-year vesting period)	120,372		83.94
Vested and paid	(77,257	)	61.36
Nonvested at December 31, 2015	256,083		$	80.43

Schedule of Restricted Stock Activity and Transactions

A summary of restricted stock award activity as of December 31, 2015, and transactions during the years ended December 31, 2015, 2014 and 2013 is presented below:

	Stock Incentive Plan
	Awards		Weighted Average Price
Nonvested at December 31, 2012	11,115		$	45.24
Restricted stock granted	52,650		52.34
Forfeited	(1,247	)	48.36
Nonvested at December 31, 2013	62,518		51.16
Restricted stock units granted	48,904		71.91
Vested	(11,848	)	65.94
Nonvested at December 31, 2014	99,574		59.60
Restricted stock units granted	99,814		65.15
Vested	(14,446	)	53.20
Nonvested at December 31, 2015	184,942		$	63.09

Schedule of Stock Option Activity and Transactions

A summary of stock option activity as of December 31, 2015, and transactions during the years ended December 31, 2015, 2014 and 2013 are presented below:

	Stock Incentive Plan
	Shares		Weighted Average Exercise Price
Outstanding at December 31, 2012	1,648,475		$	47.58
Granted	137,762		49.22
Exercised	(590,119	)	40.92
Forfeited	(5,074	)	51.85
Outstanding at December 31, 2013	1,191,044		51.06
Granted	110,307		72.55
Exercised	(544,280	)	50.09
Outstanding at December 31, 2014	757,071		54.88
Exercised	(23,680	)	41.42
Outstanding at December 31, 2015	733,391		$	55.32
Exercisable at December 31, 2013	713,445		$	49.80
Exercisable at December 31, 2014	454,938		$	51.88
Exercisable at December 31, 2015	622,156		$	53.80

Schedule of Stock Options Valuation Assumptions

Energen uses the Black-Scholes pricing model to calculate the fair values of the options awarded. For purposes of this valuation the following assumptions were used to derive the fair values:

Grant date	4/15/2014	1/22/2014	10/15/2013	1/24/2013
Awards granted	2,439	107,868	3,686	134,076
Fair market value of stock option at grant	$32.22	$27.57	$30.53	$16.66
Expected life of award	5.8 years	5.8 years	5.8 years	5.8 years
Risk-free interest rate	1.93%	2.06%	1.79%	1.01	%
Annualized volatility rate	40.7%	40.7%	40.6%	40.3	%
Dividend yield	0.2%	0.8%	0.7%	1.2	%

Schedule of Outstanding Stock Options by Range of Exercise Prices

The following table summarizes options outstanding as of December 31, 2015:

Stock Incentive Plan
Range of Exercise Prices	Shares	Weighted Average Remaining Contractual Life
$46.45	19,990	1.00 year
$60.56	48,560	2.00 years
$29.79	24,291	3.00 years
$46.69	26,481	4.00 years
$54.99	104,841	5.00 years
$54.11	271,164	6.00 years
$48.36	124,071	7.00 years
$80.48	3,686	7.79 years
$72.39	107,868	8.00 years
$79.63	2,439	8.00 years
$29.79-$80.48	733,391	5.76 years

Summary of Stock Appreciation Rights Activity

A summary of stock appreciation rights activity as of December 31, 2015, and transactions during the years ended December 31, 2015, 2014 and 2013 are presented below:

	Stock Appreciation Rights Plan
	Shares		Weighted Average Exercise Price
Outstanding at December 31, 2012	653,030		$	44.14
Granted	88,000		48.36
Exercised/forfeited	(363,653	)	39.66
Outstanding at December 31, 2013	377,377		49.48
Granted	62,749		72.39
Exercised/forfeited	(164,976	)	52.37
Outstanding at December 31, 2014	275,150		52.96
Exercised/forfeited	(10,283	)	55.18
Outstanding at December 31, 2015	264,867		$	52.88

Schedule of Stock Appreciation Rights Valuation Assumptions

For purposes of this valuation the following assumptions were used to derive the fair values as of December 31, 2015:

Grant date	1/22/2014	1/22/2014	1/24/2013	1/24/2013	1/24/2013	1/26/2011
		(modified)		(modified)	(modified)
Awards granted	62,227	522	83,654	768	3,578	182,199
Fair market value of award	$5.11	$1.67	$8.30	$5.64	$4.24	$4.80
Expected life of award	4.56 years	2.13 years	3.57 years	2.13 years	1.50 years	2.53 years
Risk-free interest rate	1.67%	1.11%	1.43%	1.11%	0.80%	1.23%
Annualized volatility rate	33.4%	33.4%	33.4%	33.4%	33.4%	33.4%
Dividend yield	0.20%	0.20%	0.20%	0.20%	0.20%	0.20%

Grant date	1/26/2011	1/27/2010	1/28/2009	2/4/2008	2/1/2007
	(modified)
Awards granted	7,785	171,749	305,257	67,093	85,906
Fair market value of award	$2.74	$5.95	$13.18	$0.81	$2.16
Expected life of award	1.50 years	2.04 years	1.54 years	1.05 years	0.54 years
Risk-free interest rate	0.80%	1.08%	0.82%	0.65%	0.54%
Annualized volatility rate	33.4%	33.4%	33.4%	33.4%	33.4%
Dividend yield	0.20%	0.20%	0.20%	0.20%	0.20%

Schedule of Incentive Units Activity

A summary of Petrotech unit activity as of December 31, 2015, and transactions during the years ended December 31, 2015, 2014 and 2013 are presented below:

	Petrotech Incentive Plan
	Shares
Outstanding at December 31, 2012	141,243
Granted (three-year vesting period)	92,418
Granted (17 month vesting period)	2,952
Paid	(36,792	)
Forfeited	(26,529	)
Outstanding at December 31, 2013	173,292
Granted	76,084
Paid	(4,431	)
Forfeited	(31,075	)
Outstanding at December 31, 2014	213,870
Granted (three-year vesting period)	128,519
Granted (two-year vesting period)	297
Granted (16 month vesting period)	1,648
Paid	(78,430	)
Forfeited	(22,158	)
Outstanding at December 31, 2015	243,746