Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Fair Value of Convertible Debt (Details)

v3.8.0.1
Fair Value Measurements - Fair Value of Convertible Debt (Details) - USD ($)
$ in Thousands
Mar. 31, 2018
Dec. 31, 2017
Fair Value | Non recurring | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Convertible debt fair value $ 466,613 $ 430,301
Carrying Value | Non recurring    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Convertible debt fair value 284,046 281,199
Term Loan And Delayed Draw Term Loan [Member] | Fair Value | Recurring | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Term Loans 312,497 303,806
Term Loan And Delayed Draw Term Loan [Member] | Carrying Value | Recurring | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Term Loans $ 315,476 $ 317,377