Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements (Details)

v3.8.0.1
Fair Value Measurements (Details) - USD ($)
$ in Thousands
 9 Months Ended
Sep. 30, 2017
Dec. 31, 2016
Dec. 15, 2014
Fair Value Measurements      
Convertible Debt, Noncurrent $ 157,353 $ 152,575  
Term Notes   100,409  
Other non-current assets      
Assets      
Gain on the underlying investment 350    
Total Assets 5,122    
Fair Value | Recurring Basis      
Assets      
Total Assets 33,301 34,382  
Liabilities      
Total liabilities 6,702 7,753  
Fair Value | Recurring Basis | Contingent consideration      
Liabilities      
Total liabilities 2,696 4,868  
Fair Value | Recurring Basis | Deferred compensation liability      
Liabilities      
Total liabilities 4,006 2,885  
Fair Value | Recurring Basis | Money market funds      
Assets      
Total Assets 28,179 31,644  
Fair Value | Recurring Basis | Asset to fund deferred compensation liability      
Assets      
Total Assets 5,122 2,738  
Fair Value | Level 1 | Recurring Basis      
Assets      
Total Assets 28,179 31,644  
Liabilities      
Total liabilities 4,006 2,885  
Fair Value | Level 1 | Recurring Basis | Deferred compensation liability      
Liabilities      
Total liabilities 4,006 2,885  
Fair Value | Level 1 | Recurring Basis | Money market funds      
Assets      
Total Assets 28,179 31,644  
Fair Value | Level 3 | Recurring Basis      
Assets      
Total Assets 5,122 2,738  
Liabilities      
Total liabilities 2,696 4,868  
Fair Value | Level 3 | Recurring Basis | Contingent consideration      
Liabilities      
Total liabilities 2,696 4,868  
Fair Value | Level 3 | Recurring Basis | Asset to fund deferred compensation liability      
Assets      
Total Assets 5,122 2,738  
Convertible Notes      
Fair Value Measurements      
Face amount 172,500 172,500 $ 172,500
Convertible Debt, Noncurrent 157,353 152,575  
Liabilities      
Total liabilities 181,142 164,824  
Convertible Notes | Carrying Value      
Fair Value Measurements      
Convertible Debt, Noncurrent 157,353 152,575  
Term Notes      
Fair Value Measurements      
Face amount   142,000  
Term Notes 0 138,335  
Liabilities      
Total liabilities 0 142,000  
Revolving credit facility      
Liabilities      
Total liabilities $ 101,168 $ 0