XML 60 R48.htm IDEA: XBRL DOCUMENT v3.8.0.1
Summary of Significant Accounting Policies - Summary of Warranty Reserve Activity Included in Accounts Payable and Accrued Liabilities (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Guarantees [Abstract]    
Balance at beginning of period $ 287 $ 312
Additions 178 233
Releases and/or charges incurred (207) (258)
Balance at end of period $ 258 $ 287