Equity-Based Compensation - Restricted Stock and RSU Awards (Details) - Restricted stock and restricted stock unit $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2019 USD ($) $ / shares shares
Number of shares
Total awarded and unvested at the beginning of the period (in shares) | shares	1,712,485
Granted (in shares) | shares	1,610,690
Vested (in shares) | shares	(718,192)
Forfeited (in shares) | shares	(307,938)
Total awarded and unvested at the end of the period (in shares) | shares	2,297,045
Weighted average grant date fair value
Total awarded and unvested at the beginning of the period (in dollars per share) | $ / shares	$ 24.57
Granted (in dollars per share) | $ / shares	8.60
Vested (in dollars per share) | $ / shares	27.70
Forfeited (in dollars per share) | $ / shares	16.56
Total awarded and unvested at the end of the period (in dollars per share) | $ / shares	$ 13.47
Additional equity compensation to be recognized over the remaining period | $	$ 25
Weighted average period for recognizing unrecognized stock-based compensation expense	2 years 7 months 6 days