Equity-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2018

Equity-Based Compensation

Schedule of equity-based compensation expense

The Company’s equity-based compensation expense, by type of award, was as follows for the three and nine months ended September 30, 2017 and 2018 (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2017		2018		2017		2018
Restricted stock unit awards	$	17,910		10,001		54,816		33,676
Stock options		614		452		1,850		1,428
Performance share unit awards		3,014		1,017		7,897		7,018
Antero Midstream phantom unit awards		4,420		4,193		12,906		12,752
Equity awards issued to directors		489		539		1,456		1,555
Total expense	$	26,447		16,202		78,925		56,429

Summary of restricted stock and restricted stock unit awards activity

		Weighted average		Aggregate
	Number of shares	grant date fair value		intrinsic value (in thousands)
Total awarded and unvested—December 31, 2017	3,424,084	$	28.51	$	65,058
Granted	668,662	$	20.74
Vested	(950,644)	$	39.30
Forfeited	(362,670)	$	25.91
Total awarded and unvested—September 30, 2018	2,779,432	$	23.29	$	49,224

Summary of stock option activity

				Weighted
		Weighted average		average remaining	Intrinsic
	Stock options	exercise price		contractual life	value (in thousands)
Outstanding at December 31, 2017	660,512	$	50.48	7.06	$	—
Granted	—	$	—
Exercised	—	$	—
Forfeited	(51,582)	$	50.00
Expired	—	$	—
Outstanding at September 30, 2018	608,930	$	50.52	6.15	$	—
Vested or expected to vest as of  September 30, 2018	608,930	$	50.52	6.15	$	—
Exercisable at September 30, 2018	481,842	$	50.66	6.05	$	—

Summary of Performance Stock Unit activity

	Number of units	Weighted average grant date fair value
Total awarded and unvested—December 31, 2017	1,283,843	$	28.29
Granted	756,466	$	23.61
Vested	(41,666)	$	27.38
Forfeited	(167,193)	$	27.85
Total awarded and unvested—September 30, 2018	1,831,450	$	26.42

Schedule of weighted average fair value assumptions used for PSUs granted

	Nine Months Ended September 30,
	2017			2018
Dividend yield		—	%		—	%
Volatility		42	%		41	%
Risk-free interest rate		1.40	%		2.49	%
Weighted average fair value of awards granted	$	26.21		$	24.85

Schedule of outstanding unvested restricted stock awards vesting schedule

	Number of units	Weighted average grant date fair value		Aggregate intrinsic value (in thousands)
Total awarded and unvested—December 31, 2017	1,042,963	$	28.69	$	30,288
Granted	260,847	$	25.84
Vested	(157,775)	$	27.65
Forfeited	(93,419)	$	28.64
Total awarded and unvested—September 30, 2018	1,052,616	$	28.15	$	30,168