Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Fair Value Measurements (Details)

v3.8.0.1
Summary of Significant Accounting Policies - Fair Value Measurements (Details) - USD ($)
$ in Thousands
Mar. 31, 2018
Dec. 31, 2017
Accounting Policies [Abstract]    
Long-term debt carrying value $ 208,136 $ 160,108
Level 2    
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]    
Carrying value of fixed-rate long-term debt in excess of fair value $ 718