XML 49 R39.htm IDEA: XBRL DOCUMENT v3.7.0.1
Debt - Additional Information (Details)
Jun. 30, 2017
USD ($)
Dec. 31, 2016
USD ($)
Debt Instrument [Line Items]    
Revolving credit facility $ 45,000,000 $ 52,500,000
Consolidated fixed charge coverage ratio 3.30  
Bank covenant, fixed charge coverage ratio 1.5  
Fixed Rate Debt    
Debt Instrument [Line Items]    
Estimated fair value of debt $ 537,900,000 516,000,000
Variable rate debt    
Debt Instrument [Line Items]    
Estimated fair value of debt 45,000,000 52,500,000
Senior Unsecured Revolving Credit Facility    
Debt Instrument [Line Items]    
Revolving credit facility 45,000,000 $ 52,500,000
Maximum borrowing availability under revolving credit facility $ 250,000,000.0