XML 49 R36.htm IDEA: XBRL DOCUMENT v3.8.0.1
Debt - Availability Under The Senior Credit Facility (Details) - USD ($)
$ in Thousands
Sep. 30, 2017
Jun. 30, 2017
Dec. 31, 2016
Debt Disclosure [Abstract]      
Senior credit facility $ 300,000 $ 300,000 $ 250,000
Capacity Constraint Due To Senior Leverage Ratio 164,084 169,092  
Line Of Credit Facility Maximum Borrowing Capacity After Consideration Of Capacity Constraint 135,916 130,908  
Line of Credit Facility, Amount Outstanding 42,076 44,682  
Letters of credit subject to the credit facility 8,133 7,825  
Availability under the senior credit facility $ 85,707 $ 78,401