Quarterly report pursuant to Section 13 or 15(d)

Long-Term Debt (Senior Credit Facility) (Details)

v3.8.0.1
Long-Term Debt (Senior Credit Facility) (Details)
3 Months Ended
Mar. 31, 2018
USD ($)
Term Loan | Term Loan B  
Line of Credit Facility [Line Items]  
Line of credit availability $ 245,900,000.0
Interest rate 2.25%
Principal payments, a percentage of the original principal amount 0.25%
Line of credit outstanding balance $ 242,000,000
Term Loan | Term Loan A  
Line of Credit Facility [Line Items]  
Line of credit availability $ 215,000,000
Total leverage ratio 5.95
Senior leverage ratio 3.50
Interest coverage ratio 2.50
Line of credit outstanding balance $ 215,000,000
Term Loan | Term Loan A | LIBOR | Minimum  
Line of Credit Facility [Line Items]  
Variable interest rate 2.00%
Term Loan | Term Loan A | LIBOR | Maximum  
Line of Credit Facility [Line Items]  
Variable interest rate 3.00%
Senior Credit Facility  
Line of Credit Facility [Line Items]  
Remainder amount available for borrowing $ 79,900,000
Senior Credit Facility | Revolving Credit Facility  
Line of Credit Facility [Line Items]  
Line of credit availability 300,000,000
Line of credit outstanding balance 210,000,000
Senior Credit Facility | Letters of Credit  
Line of Credit Facility [Line Items]  
Line of credit outstanding balance $ 10,100,000