Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Narrative (Details)

v3.8.0.1
Fair Value Measurements - Narrative (Details) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Mar. 31, 2018
Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Income tax expense benefit on interest rate swap $ 132 $ 113
Other current assets | Fair Value, Measurements, Recurring | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Interest rate swap agreements $ 524 $ 294