v3.10.0.1
Derivative Instruments and Fair Value Measurements - Summary of Financial Instruments Not Recorded at Fair Value (Detail)
$ in Thousands
Sep. 30, 2018
USD ($)
Carrying Amount  
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]  
Senior Notes $ 84,411
Fair Value  
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]  
Senior Notes $ 82,855