Stockholders' Deficit - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions			12 Months Ended
	Jun. 19, 2017	Jan. 01, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for awards under incentive compensation plan (in shares)		2,000,000.0
Maximum employee subscription rate		15.00%
Discount from market price		15.00%
Shares issued			54,000
Average price of shares issues (in usd per share)			$ 30.63
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period from first anniversary of grant			4 years
Award expiration period			10 years
Stock-based compensation expense recognized			$ 3.7	$ 6.4	$ 2.2
Stock options granted (in shares)			700,000.0
Grants, weighted average grant date fair value (in usd per share)			$ 22.17
Fair value of options granted			$ 8.0
Unrecognized stock-based compensation expense relating to unvested awards that will be amortized			$ 9.0
Unvested stock options (in shares)			1,800,000
Weighted-average period of amortization			2 years
Average remaining contract term			8 years 5 months
Options exercisable at end of period (in usd per share)			$ 14.11
Cash received from exercise of stock options			$ 8.7
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period from first anniversary of grant			4 years
Stock-based compensation expense recognized			$ 23.0	$ 28.8	$ 22.9
Unrecognized stock-based compensation expense relating to unvested awards that will be amortized			$ 33.2
Weighted-average period of amortization			2 years
2003 Incentive Compensation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for awards under incentive compensation plan (in shares)			19,400,000
Shares available for grant (in shares)			3,600,000
Preexisting Incentive Compensation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for issuance (less than)			100,000.0
Series C Preferred Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for issuance (in shares)	20,000
Preferred par value (in usd per share)	$ 0.001
Shares holders are entitled to (in shares)	0.0001
Exercise price of rights (in usd per share)	$ 109.00
Preferred shares outstanding (in shares)			0
Series A Preferred Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred par value (in usd per share)	$ 0.01
Preferred Share Purchase Right | Series A Preferred Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred dividend (in shares)	1
Preferred shares issued on exercise (in shares)			0