Stock-based Compensation Plans (Tables)

12 Months Ended

Dec. 31, 2021

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, 2021 (in thousands):

	2021		2020		2019
Direct operating expense	$	1,310	$	1,078	$	1,928
Brokered natural gas and marketing expense		1,794		1,416		1,856
Exploration expense		1,507		1,279		1,566
General and administrative expense		39,673		32,905		35,061
Termination costs		—		2,165		1,971
Total stock-based compensation	$	44,284	$	38,843	$	42,382

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, 2021:

	Restricted Stock Equity Awards					Restricted Stock Liability Awards
	Shares			Weighted Average Grant Date Fair Value		Shares			Weighted Average Grant Date Fair Value
Outstanding at December 31, 2020		2,815,860		$	4.97		1,186,636		$	4.18
Granted		2,340,114			10.20		1,289,495			9.56
Vested		(2,397,336	)		7.33		(1,679,502	)		7.21
Forfeited		(83,861	)		6.32		—			—
Outstanding at December 31, 2021		2,674,777		$	7.39		796,629		$	6.49

Schedule of Share Based Payment Award Performance Stock Awards Valuation Assumptions

The following assumptions were used to estimate the fair value of the TSR awards granted during the years ended December 31, 2021, 2020 and 2019:

	Year Ended December 31,
	2021			2020			2019
Risk-free interest rate		0.2	%		1.4	%		2.4	%
Expected annual volatility		75	%		65	%		46	%
Grant date fair value per unit	$	12.58		$	3.85		$	11.34

Summary of Change in Post Retirement Benefit Obligation

The change in our post-retirement benefit obligation is as follows (in thousands):

Change in Benefit Obligation:	2021			2020
Benefit obligation at beginning of year	$	1,953		$	1,957
Service cost		77			80
Interest cost		38			50
Actuarial (gain) loss		(62	)		(39	)
Benefits paid		(88	)		(95	)
Benefit obligation at end of year	$	1,918		$	1,953
Amounts recognized in the consolidated balance sheet:
Long-term liabilities	$	1,918		$	1,953
Components of Net Periodic Post Retirement Benefit Cost:
Service cost	$	77		$	80
Interest cost		38			50
Amortization of prior service cost		369			369
Net periodic post retirement costs (recognized in general and    administrative expense)	$	484		$	499
Other Changes in Benefit Obligations in Other Comprehensive    Income (Loss):
Net (gain) loss	$	(62	)	$	(39	)
Prior service cost		—			—
Amortization of prior service cost		(369	)		(369	)
Total recognized in other comprehensive (loss) income	$	(431	)	$	(408	)
Total recognized in net periodic benefit cost and other comprehensive    income	$	53		$	91

Summary of Assumptions Used to Determine Benefit Obligation

The following summarizes the assumptions used to determine the benefit obligation at December 31, 2021 and 2020:

	December 31, 2021			December 31, 2020
Weighted average assumptions used to determine benefit obligation:
Discount rate		2.5	%		1.9	%
Assumed weighted average healthcare cost trend rates:
Initial healthcare trend rate		7.0	%		6.5	%
Ultimate trend rate		4.0	%		4.5	%
Year ultimate trend rate reached	2033			2024

Performance-based Internal Performance Awards

Summary of Non-Vested Awards Activities

The following is a summary of our non-vested internal performance metric awards activities at December 31, 2021:

	Number of Units			Weighted Average Grant Date Fair Value
Outstanding at December 31, 2020		1,099,102		$	5.92
Units granted (a)		303,231			9.81
Vested		(306,978	)		12.20
Forfeited (b)		—			—
Outstanding at December 31, 2021		1,095,355		$	7.80

(a)Amounts granted reflect the number of performance units granted; however, the actual payout of shares will be between zero and 200% depending on achievement of specifically identified performance targets.

(b)For Production Growth units granted in 2019 which are set to vest in early 2022, the payout is estimated at 74%. For Reserve Growth units granted in 2019 which are set to vest in early 2022, the payout is estimated at 121%.

Performance Based TSR - PSUs

Summary of Non-Vested Awards Activities

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

	Number of Units			Weighted Average Grant Date Fair Value
Outstanding at December 31, 2020		1,249,524		$	9.55
Granted (a)		223,687			12.58
Vested and issued (b)		(325,217	)		18.51
Forfeited		—			—
Outstanding at December 31, 2021		1,147,994		$	7.60

(a)These amounts reflect the number of performance units granted. The actual payout of shares may be between zero and 200% of the performance units granted depending on the total shareholder return ranking compared to our peer companies at the vesting date.

(b)Includes TSR-PSUs awards issued related to the 2018 performance period where the return on our common stock was negative and therefore, the performances multiple and actual payout was reduced to 100%.