Equity-Based Compensation - Restricted Stock and RSU Awards (Details) - Restricted stock awards $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) $ / shares shares
Number of shares
Total granted and unvested at the beginning of the period (in shares) | shares	3,424,084
Granted (in shares) | shares	687,626
Vested (in shares) | shares	(1,933,130)
Forfeited (in shares) | shares	(466,095)
Total awarded and unvested at the end of the period (in shares) | shares	1,712,485
Weighted average grant date fair value
Total granted and unvested at the beginning of the period (in dollars per share) | $ / shares	$ 28.51
Granted (in dollars per share) | $ / shares	20.69
Vested (in dollars per share) | $ / shares	29.90
Forfeited (in dollars per share) | $ / shares	25.65
Total awarded and unvested at the end of the period (in dollars per share) | $ / shares	$ 24.57
Aggregate intrinsic value
Total awarded and unvested at the beginning of the period | $	$ 65,058
Total awarded and unvested at the end of the period | $	16,080
Additional equity compensation to be recognized over the remaining period | $	$ 27,000
Weighted average period for recognizing unrecognized stock-based compensation expense	2 years 3 months 18 days