Stockholders' Equity (Tables)

6 Months Ended

Jun. 30, 2019

Stockholders' Equity Note [Abstract]

Restricted share activity

Activity for RSAs, performance stock awards (“PSAs”) and PSUs is summarized below:

	RSAs		PSAs		PSUs		Total		Weighted Average Grant Date Fair Value
Unvested balance, December 31, 2018	399,795		3,132		201,383		604,310		$	71.50
Granted	218,245		—		138,994		357,239		137.42
Vested	(129,526	)	(3,132	)	(10,528	)	(143,186	)	70.57
Forfeited	(29,597	)	—		(5,010	)	(34,607	)	83.05
Unvested balance, June 30, 2019	458,917		—		324,839		783,756		$	101.20

The aggregate fair values of RSAs, PSUs and PSAs granted and vested are presented in the following table:

	Six Months Ended June 30,
	2019		2018
	(In millions)
Granted:
RSAs	$	30	$	25
PSUs	19		16
Total granted	$	49	$	41
Vested:
RSAs	$	18	$	14
PSUs	2		—
PSAs	—		3
Total vested	$	20	$	17