Stock-based Compensation Plans (Tables)

12 Months Ended

Dec. 31, 2016

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Allocation of Stock-Based Compensation by Functional Category

The following table details the amount of stock-based compensation that is allocated to functional expense categories for each of the years in the three-year period ended December 31, 2016 (in thousands):

	2016		2015			2014
Direct operating expense	$	2,302		$	2,780		$	4,208
Brokered natural gas and marketing expense		1,725			2,132			3,523
Exploration expense		2,298			2,985			4,569
General and administrative expense		49,293			49,687			55,382
Termination costs		—			217			2,999
Total	$	55,618		$	57,801		$	70,681

Summary of Performance Share Unit Awards Activities

The following is a summary of our non-vested PSU award activities:

	Number of Units (a)			Weighted Average Grant Date Fair Value
Outstanding at December 31, 2013		—			—
Granted		227,929		$	86.14
Vested (b)		(92,077	)		86.23
Forfeited		(1,511	)		82.60
Outstanding at December 31, 2014		134,341			86.11
Granted		276,204			56.78
Vested (c)		(143,094	)		68.73
Forfeited		(5,327	)		82.60
Outstanding at December 31, 2015		262,124			64.77
Granted		413,959			36.64
Vested (c)		(237,572	)		53.07
Forfeited		(42,603	)		46.09
Outstanding at December 31, 2016		395,908		$	44.39

^(a) These amounts reflect the number of performance units granted. The actual payout of shares may be between zero percent and 150% of the performance units granted depending on the total shareholder return ranking compared to our peer companies at the vesting date.

^(b) Primarily represents PSU awards granted to our prior executive chairman for the 2013 calendar year while he was a Range officer.

^(c) Includes PSU awards of 19,684 that were modified and fully vested effective with the closing of our Oklahoma City Office and the sale of our Virginia and West Virginia assets.

Schedule of Share Based Payment Award Performance Stock Awards Valuation Assumptions

The following assumptions were used to estimate the fair value of PSUs granted during the years ended December 31, 2016, 2015 and 2014:

	Year Ended December 31, 2016
	2016			2015			2014
Risk-free interest rate		0.94	%		1.02	%		0.77	%
Expected annual volatility		49	%		33	%		33	%
Grant date fair value per unit	$	36.64		$	56.78		$	86.14

Restricted Stock and Restricted Stock Units Outstanding

The following is a summary of the status of our non-vested restricted stock outstanding at December 31, 2016:

	Equity Awards					Liability Awards
	Shares			Weighted Average Grant Date Fair Value		Shares			Weighted Average Grant Date Fair Value
Outstanding at December 31, 2013		385,063		$	68.24		389,013		$	71.02
Granted		356,194			84.87		272,052			87.34
Vested		(354,237	)		72.85		(356,413	)		75.52
Forfeited		(26,605	)		75.66		(148	)		77.35
Outstanding at December 31, 2014		360,415			79.60		304,504			80.33
Granted		587,711			52.29		343,397			55.92
Vested		(480,253	)		65.21		(330,870	)		68.71
Forfeited		(31,109	)		64.73		(8,294	)		74.22
Outstanding at December 31, 2015		436,764			59.74		308,737			65.80
Granted		973,491			28.51		540,128			35.92
Vested		(525,617	)		43.83		(374,328	)		51.40
Forfeited		(118,667	)		42.60		(49,519	)		40.33
Outstanding at December 31, 2016		765,971		$	33.62		425,018		$	43.48

Stock Option and SARs Activities

Information with respect to our SARs activities is summarized below.

	Shares			Weighted Average Exercise Price
Outstanding at December 31, 2013		2,582,074		$	56.36
Granted		1,104			81.74
Exercised		(616,563	)		45.45
Expired/forfeited		(66	)		46.44
Outstanding at December 31, 2014		1,966,549			59.80
Exercised		(427,598	)		45.67
Expired/forfeited		(27,974	)		63.10
Outstanding at December 31, 2015		1,510,977			63.73
Exercised		—			—
Expired/forfeited		(507,377	)		53.16
Outstanding at December 31, 2016		1,003,600		$	69.08

Summary of SARs Outstanding and Exercisable

The following table shows information with respect to SARs outstanding and exercisable at December 31, 2016:

	Outstanding						Exercisable
Range of Exercise Prices	Shares		Weighted Average Remaining Contractual Life (in years)		Weighted Average Exercise Price		Shares		Weighted Average Exercise Price
$ 40.00–$ 49.99		10,108		0.04	$	49.18		10,108	$	49.18
50.00–59.99		—		—		—		—		—
60.00–69.99		578,064		0.36		64.23		578,064		64.23
70.00–79.99		413,528		1.28		76.29		413,528		76.29
80.00–81.15		1,900		1.69		81.15		1,900		81.15
Total		1,003,600		0.74	$	69.08		1,003,600	$	69.08

Weighted Average Grant Date Fair Value of SARs

The weighted average grant date fair value of these SARs, based on our Black-Scholes-Merton assumptions, is shown below:

	2014
Weighted average exercise price per share	$	81.74
Expected annual dividend yield		0.20	%
Expected life in years		4.3
Expected volatility		33	%
Risk-free interest rate		1.4	%
Weighted average grant date fair value per share	$	23.17