Shareholders' Equity and Stock Incentive Plans (Tables)

3 Months Ended

Mar. 31, 2017

Shareholders' Equity and Stock Incentive Plans [Abstract]

Schedule of Restricted Stock Awards and Restricted Stock Units Activity

The table below summarizes restricted stock award and unit activity for the first quarter of 2017:

	Restricted Stock Awards and Units		Weighted Average Grant Date Fair Value
For the Three Months Ended March 31, 2017
Unvested restricted stock awards and units, beginning of period	1,111,710			$36.93
Granted	749,396			$27.07
Vested	(569,145	)		$39.48
Forfeited	(3,933	)		$29.42
Unvested restricted stock awards and units, end of period	1,288,028			$30.09

Schedule of Stock Appreciation Rights Award Activity

The table below summarizes the activity for SARs for the first quarter of 2017:

	Stock Appreciation Rights		Weighted Average Exercise Prices		Weighted Average Remaining Life (In years)	Aggregate Intrinsic Value (In millions)		Aggregate Intrinsic Value of Exercises (In millions)
For the Three Months Ended March 31, 2017
Outstanding, beginning of period	722,638			$23.69
Granted	342,440			$26.94
Exercised	(100,000	)		$17.28					$1.3
Forfeited	—		—
Outstanding, end of period	965,078			$25.51	3.4		$2.5
Exercisable, end of period	436,739			$23.62	1.8		$2.0

Schedule of Stock Appreciation Rights Valuation Assumptions

The following table summarizes the assumptions used to calculate the grant date fair value of SARs granted during the first quarter of 2017:

	Grant Date Fair Value Assumptions
Expected term (in years)	4.24
Expected volatility	54.3	%
Risk-free interest rate	1.8	%
Dividend yield	—	%
Grant date fair value	$12.00

Schedule of Performance Shares Award Unvested Activity

The table below summarizes performance share activity for the first quarter of 2017:

	Performance Shares		Weighted Average Grant Date Fair Value
For the Three Months Ended March 31, 2017
Unvested performance shares, beginning of period	154,510			$58.44
Granted	46,787			$35.14
Vested (1)	(56,342	)		$68.15
Forfeited	—		—
Unvested performance shares, end of period	144,955			$47.14

Schedule of Performance Share Award Valuation Assumptions

The following table summarizes the assumptions used to calculate the grant date fair value of the performance shares granted during the first quarter of 2017:

	Grant Date Fair Value Assumptions
Number of simulations	500,000
Expected term (in years)	2.98
Expected volatility	59.2	%
Risk-free interest rate	1.5	%
Dividend yield	—	%
Grant date fair value	$35.14

Schedule of Stock-based Compensation, net

The Company recognized the following stock-based compensation expense, net for the periods indicated:

	Three Months Ended March 31,
	2017			2016
	(In thousands)
Restricted stock awards and units		$5,849			$11,594
Stock appreciation rights	(3,686		)	1,232
Performance shares	706			616
	2,869			13,442
Less: amounts capitalized to oil and gas properties	(855		)	(1,920		)
Total stock-based compensation expense, net		$2,014			$11,522