Annual report pursuant to Section 13 and 15(d)

Subsequent Events (Details)

v3.8.0.1
Subsequent Events (Details)
 1 Months Ended
Mar. 08, 2018
USD ($)
$ / shares
shares
Feb. 28, 2015
Dec. 31, 2017
USD ($)
$ / shares
Sep. 30, 2017
USD ($)
Dec. 31, 2016
USD ($)
$ / shares
Dec. 31, 2015
shares
Subsequent Event [Line Items]            
Number of shares issuable | shares           3,957,280
Common stock, par value (in dollars per share)     $ 0.0001   $ 0.0001  
Debt | $     $ 660,200,000      
Convertible senior notes            
Subsequent Event [Line Items]            
Debt | $     $ 82,500,000 $ 82,500,000 $ 82,500,000  
Cash interest rate   2.75% 2.75% 2.75%    
Convertible senior notes | From fourth anniversary to fifth anniversary of closing date            
Subsequent Event [Line Items]            
Redemption price as a percent   100.00%        
Convertible senior notes | From fifth anniversary and thereafter of closing date            
Subsequent Event [Line Items]            
Redemption price as a percent   100.00%        
Revolving Credit Facility            
Subsequent Event [Line Items]            
Debt | $     $ 78,000,000      
Subsequent Event | Second Lien Notes            
Subsequent Event [Line Items]            
Debt issued | $ $ 150,000,000          
Paid-in-kind interest rate 12.00%          
Cash interest rate 10.00%          
Covenant net leverage ratio, minimum 3.39          
Subsequent Event | Second Lien Notes | Prior to third anniversary of closing date            
Subsequent Event [Line Items]            
Redemption price as a percent 100.00%          
Subsequent Event | Second Lien Notes | From third anniversary to fourth anniversary of closing date            
Subsequent Event [Line Items]            
Redemption price as a percent 105.00%          
Subsequent Event | Second Lien Notes | From fourth anniversary to fifth anniversary of closing date            
Subsequent Event [Line Items]            
Redemption price as a percent 102.50%          
Subsequent Event | Second Lien Notes | From fifth anniversary and thereafter of closing date            
Subsequent Event [Line Items]            
Redemption price as a percent 100.00%          
Subsequent Event | Second Lien Notes | Upon a change in control            
Subsequent Event [Line Items]            
Redemption price as a percent 101.00%          
Subsequent Event | Equity warrants            
Subsequent Event [Line Items]            
Debt issued | $ $ 150,000,000          
Maximum ownership percentage before exercise of warrants is restricted 19.90%          
Subsequent Event | Convertible senior notes            
Subsequent Event [Line Items]            
Cash interest rate 2.75%          
Maximum ownership percentage before exercise of warrants is restricted 9.90%          
Subsequent Event | Penny Warrants | Equity warrants            
Subsequent Event [Line Items]            
Number of shares issuable | shares 18,065,775          
Common stock, par value (in dollars per share) $ 0.0001          
Warrant exercise price (in dollars per share) 0.01          
45-day volume-weighted average price trigger to be exercisable $ 4.00          
Subsequent Event | Penny Warrants | Equity warrants | Minimum            
Subsequent Event [Line Items]            
Maximum ownership percentage before exercise of warrants is restricted 50.00%          
Percentage of Warrants Held to Nominate for Board of Directors 25.00%          
Subsequent Event | Penny Warrants | Equity warrants | Maximum            
Subsequent Event [Line Items]            
Percentage of Warrants Held to Nominate for Board of Directors 50.00%          
Subsequent Event | Market Warrants | Equity warrants            
Subsequent Event [Line Items]            
Number of shares issuable | shares 13,000,000          
Warrant exercise price (in dollars per share) $ 1.57          
45-day volume-weighted average price trigger to be exercisable $ 2.40          
Subsequent Event | Market Warrants | Equity warrants | Minimum            
Subsequent Event [Line Items]            
Maximum ownership percentage before exercise of warrants is restricted 25.00%