Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements (Details)

v3.8.0.1
Fair Value Measurements (Details) - Fair Value, Measurements, Recurring - USD ($)
$ in Thousands
Mar. 31, 2018
Dec. 31, 2017
Level 1 | Other assets    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Non-COLI assets held in Deferred Supplemental Compensation Plan $ 395 $ 389
Level 2 | Other current assets    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Interest rate swap agreements $ 524 $ 294