Quarterly report pursuant to Section 13 or 15(d)

Long-Term Debt (Schedule Of Long-Term Debt) (Details)

v3.5.0.2
Long-Term Debt (Schedule Of Long-Term Debt) (Details) - USD ($)
$ in Thousands
Sep. 30, 2016
Dec. 31, 2015
Sep. 30, 2015
Jan. 27, 2015
Dec. 31, 2014
Debt Instrument [Line Items]          
Long-term debt, net of unamortized deferred financing costs $ 625,687 $ 633,108 $ 692,660    
Less: current maturities (25,000) (25,000) (18,750)    
Long-term debt, less current maturities and net of unamortized deferred financing costs 600,687 608,108 673,910    
Revolving credit facility [Member]          
Debt Instrument [Line Items]          
Secured credit 150,000 140,000 200,000    
Credit Agreement Terminated January 27, 2015 [Member]          
Debt Instrument [Line Items]          
Long-term Debt, Gross       $ 228,100  
Unamortized deferred financing costs       (1,900) $ (2,400)
Credit Agreement 1.25B [Member]          
Debt Instrument [Line Items]          
Secured credit       1,250,000  
Long-term Debt, Gross 631,250 640,000 700,000    
Unamortized deferred financing costs (5,563) (6,892) (7,340) (6,600)  
Credit Agreement 1.25B [Member] | Long-term Debt [Member]          
Debt Instrument [Line Items]          
Secured credit 481,250 500,000 500,000 $ 500,000  
Credit Agreement 1.25B [Member] | Revolving credit facility [Member]          
Debt Instrument [Line Items]          
Secured credit $ 150,000 $ 140,000 $ 200,000