Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements (Details)

v3.7.0.1
Fair Value Measurements (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2017
Dec. 31, 2016
Nov. 19, 2015
Dec. 15, 2014
Fair Value Measurements        
Income or expense on deferred compensation asset $ 0      
Convertible Debt, Noncurrent 154,146 $ 152,575    
Term Notes $ 70,448 100,409    
Liabilities        
Debt instrument covenant, prepayment term 90 days      
Debt instrument covenant, leverage ratio 2.00%      
Excess cash flow payment $ 31,862      
Non-current liabilities, other        
Assets        
Total Assets 3,761      
Fair Value | Recurring Basis        
Assets        
Total Assets 21,444 34,382    
Liabilities        
Total liabilities 6,598 7,753    
Fair Value | Recurring Basis | Contingent consideration        
Liabilities        
Total liabilities 2,700 4,868    
Fair Value | Recurring Basis | Deferred compensation liability        
Liabilities        
Total liabilities 3,898 2,885    
Fair Value | Recurring Basis | Money market funds        
Assets        
Total Assets 17,683 31,644    
Fair Value | Recurring Basis | Asset to fund deferred compensation liability        
Assets        
Total Assets 3,761 2,738    
Fair Value | Level 1 | Recurring Basis        
Assets        
Total Assets 17,683 31,644    
Liabilities        
Total liabilities 3,898 2,885    
Fair Value | Level 1 | Recurring Basis | Deferred compensation liability        
Liabilities        
Total liabilities 3,898 2,885    
Fair Value | Level 1 | Recurring Basis | Money market funds        
Assets        
Total Assets 17,683 31,644    
Fair Value | Level 3 | Recurring Basis        
Assets        
Total Assets 3,761 2,738    
Liabilities        
Total liabilities 2,700 4,868    
Fair Value | Level 3 | Recurring Basis | Contingent consideration        
Liabilities        
Total liabilities 2,700 4,868    
Fair Value | Level 3 | Recurring Basis | Asset to fund deferred compensation liability        
Assets        
Total Assets 3,761 2,738    
Convertible Notes        
Fair Value Measurements        
Face amount       $ 172,500
Convertible Debt, Noncurrent 154,146 152,575    
Liabilities        
Total liabilities 160,817 164,824    
Convertible Notes | Carrying Value        
Fair Value Measurements        
Convertible Debt, Noncurrent 154,146 152,575    
Term Notes        
Fair Value Measurements        
Face amount     $ 160,000  
Term Notes 105,669 138,335    
Liabilities        
Total liabilities 108,138 142,000    
Revolving credit facility        
Liabilities        
Total liabilities $ 25,000 $ 0