Stockholders' Equity - Summary of RSU and PSU Activity Under Equity-Based Plans (Details)	12 Months Ended
	Dec. 31, 2017 $ / shares shares
RSUs
Number of Units
Balance (in shares) | shares	2,323,051
Granted (in shares) | shares	1,231,507
Vested (in shares) | shares	(1,012,834)
Forfeited (in shares) | shares	(292,063)
Balance (in shares) | shares	2,249,661
Weighted-Average Grant Date Fair Value
Balance (in dollars per share) | $ / shares	$ 20.32
Granted (in dollars per share) | $ / shares	29.73
Vested (in dollars per share) | $ / shares	20.93
Forfeited (in dollars per share) | $ / shares	23.14
Balance (in dollars per share) | $ / shares	$ 24.83
PSUs
Number of Units
Balance (in shares) | shares	149,412
Granted (in shares) | shares	330,674
Vested (in shares) | shares	(7,518)
Forfeited (in shares) | shares	(18,894)
Balance (in shares) | shares	453,674
Weighted-Average Grant Date Fair Value
Balance (in dollars per share) | $ / shares	$ 33.51
Granted (in dollars per share) | $ / shares	29.69
Vested (in dollars per share) | $ / shares	33.51
Forfeited (in dollars per share) | $ / shares	33.51
Balance (in dollars per share) | $ / shares	$ 30.72