Common Stock Common Stock (Tables)

3 Months Ended

Mar. 31, 2020

Share-based Payment Arrangement, Cost by Plan [Table Text Block]

The following table provides a summary of the impact of our outstanding stock-based compensation plans on the results of operations for the periods presented:



	Three Months Ended March 31,
	2020			2019
	(in thousands)

Stock-based compensation expense	$	5,672		$	4,683
Income tax benefit	(1,375		)	(1,120		)
Net stock-based compensation expense	$	4,297		$	3,563

Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block]

The following table presents the changes in non-vested time-based RSUs to all employees, including executive officers, for the three months ended March 31, 2020:



	Shares		Weighted-Average Grant Date Fair Value per Share

Non-vested at December 31, 2019	795,926		$	45.51
Granted	316,778		22.73
Vested	(168,998	)	47.34
Forfeited	(21,927	)	44.89
Non-vested at March 31, 2020	921,779		37.36

The following table presents the weighted-average grant date fair value per share and related information as of/for the periods presented:



	As of/Three Months Ended March 31,
	2020		2019
	(in thousands, except per share data)

Total intrinsic value of time-based awards vested	$	3,748	$	3,311
Total intrinsic value of time-based awards non-vested	5,724		28,544
Market price per share as of March 31	6.21		40.68
Weighted-average grant date fair value per share	22.73		38.59

Restricted Stock Awards, Market-Based, Valuation assumptions [Table Text Block]

The Compensation Committee awarded a total of 278,889 market-based PSUs to our executive officers during the three months ended March 31, 2020. In addition to continuous employment, the vesting of these PSUs is contingent on a combination of absolute stock performance and our total stockholder return ("TSR"), which is essentially our stock price change including any dividends over a three-year period ending on December 31, 2022, as compared to the TSR of a group of peer companies over the same period. The PSUs will result in a payout between zero and 250 percent of the target PSUs awarded. The weighted-average grant date fair value per PSU granted was computed using the Monte Carlo pricing model using the following assumptions:



	Three Months Ended March 31,
	2020		2019

Expected term of award (in years)	3		3
Risk-free interest rate	1.4	%	2.5	%
Expected volatility	46.6	%	41.4	%

The expected term of the awards was based on the requisite service period. The risk-free interest rate was based on the U.S. Treasury yields in effect at the time of grant and extrapolated to approximate the life of the award. The expected volatility was based on our historical volatility.

SRC Performance Stock Units. Terms of the SRC PSUs are substantially the same as PDC PSUs, except that the awards do not require continuous employment and the performance period associated with the awards of January 1, 2019 through December 31, 2021, predates the grant date. The fair value of the SRC PSU awards was determined on the grant date of January 13, 2020 using the Monte Carlo pricing model using the following assumptions:



	Three Months Ended March 31,
	2020

Expected term of awards (in years)	2
Risk-free interest rate	1.6		%
Expected volatility	56.9		%
Weighted-average grant date fair value per share	$	33.35

Schedule of Nonvested Performance-based Units Activity [Table Text Block]

The following table presents the change in non-vested market-based awards, including SRC PSUs, during the three months ended March 31, 2020:



	Shares	Weighted-Average Grant Date Fair Value per Share

Non-vested at December 31, 2019	221,142	$	61.61
Granted	434,817	33.46
Non-vested at March 31, 2020	655,959	42.95

The following table presents the weighted-average grant date fair value per share and related information as of/for the periods presented:



	As of/Three Months Ended March 31,
	2020		2019
	(in thousands, except per share data)

Total intrinsic value of market-based awards non-vested	$	4,074	$	9,849
Market price per common share as of March 31,	6.21		40.68
Weighted-average grant date fair value per share	33.46		56.68