Annual report pursuant to Section 13 and 15(d)

Long-Term Debt - Key Terms of Credit Agreement (Details)

v3.8.0.1
Long-Term Debt - Key Terms of Credit Agreement (Details) - USD ($)
$ in Thousands
12 Months Ended
May 05, 2017
Dec. 31, 2017
Dec. 31, 2016
Long-Term Debt      
Loss on extinguishment of debt   $ 1,086  
Amount outstanding   243,750  
New Credit Agreement      
Long-Term Debt      
Additional term loan and/or revolver capacity available under incremental facility   200,000  
New Credit Agreement | Minimum      
Long-Term Debt      
Commitment fee (as a percent) 0.15%    
New Credit Agreement | Maximum      
Long-Term Debt      
Commitment fee (as a percent) 0.275%    
New Credit Agreement | Term Loan Facility      
Long-Term Debt      
Availability   250,000  
Additional term loan capacity under delayed draw feature   100,000  
Line of Credit Facility Maximum Borrowing Capacity Including Delayed Draw $ 350,000    
Amount outstanding $ 250,000    
New Credit Agreement | Revolving Facility      
Long-Term Debt      
Availability   250,000 $ 125,000
Sublimit for issuance of letters of credit under Revolving Facility*   100,000  
Sublimit for swingline loans under Revolving Facility*   $ 20,000  
Interest rate   2.85%  
New Credit Agreement | Base Rate Borrowings | Minimum      
Long-Term Debt      
Applicable margin based on total leverage ratio 0.00%    
New Credit Agreement | Base Rate Borrowings | Maximum      
Long-Term Debt      
Applicable margin based on total leverage ratio 1.50%    
New Credit Agreement | LIBOR Rate Borrowings | Minimum      
Long-Term Debt      
Applicable margin based on total leverage ratio 1.00%    
New Credit Agreement | LIBOR Rate Borrowings | Maximum      
Long-Term Debt      
Applicable margin based on total leverage ratio 2.50%    
Federal Funds Rate | New Credit Agreement | Base Rate Borrowings      
Long-Term Debt      
Basis spread 0.50%    
LIBOR | New Credit Agreement | Base Rate Borrowings      
Long-Term Debt      
Basis spread 1.00%    
Maturity of the reference rate 1 month