Quarterly report pursuant to Section 13 or 15(d)

Changes in Accumulated Other Comprehensive Loss by Component - Reclassifications (Details)

v3.8.0.1
Changes in Accumulated Other Comprehensive Loss by Component - Reclassifications (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Amounts reclassified from accumulated other comprehensive loss:    
Interest expense, net $ 3,945 $ 5,296
Tax expense (benefit) (1,262) (2,694)
Reclassification net of tax 1,850 3,233
Interest rate swap | Amount reclassified from accumulated other comprehensive income    
Amounts reclassified from accumulated other comprehensive loss:    
Interest expense, net   97
Tax expense (benefit)   (37)
Reclassification net of tax   60
Other Postretirement Benefit Liability | Amount reclassified from accumulated other comprehensive income    
Amounts reclassified from accumulated other comprehensive loss:    
Actuarial (gains) losses (52) (27)
Tax expense (benefit) 14 10
Reclassification net of tax (38) (17)
Pension Liability | Amount reclassified from accumulated other comprehensive income    
Amounts reclassified from accumulated other comprehensive loss:    
Actuarial (gains) losses 176 181
Tax expense (benefit) (46) (69)
Reclassification net of tax 130 $ 112
Unrealized Net Loss on Interest Rate Swap | Interest rate swap    
Amounts reclassified from accumulated other comprehensive loss:    
Interest expense, net 29  
Tax expense (benefit) (8)  
Reclassification net of tax $ 21