XML 58 R46.htm IDEA: XBRL DOCUMENT v3.19.1
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, 2018
Dec. 31, 2017
Guarantees [Abstract]    
Balance at beginning of period $ 258 $ 287
Additions 108 178
Releases and/or charges incurred (171) (207)
Balance at end of period $ 195 $ 258