Quarterly report pursuant to Section 13 or 15(d)

Changes in Initial Product Warranty Accrual and Expenses Under Initial and Extended Warranties (Detail)

v3.10.0.1
Changes in Initial Product Warranty Accrual and Expenses Under Initial and Extended Warranties (Detail) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
Dec. 31, 2017
Movement in Standard Product Warranty Accrual          
Initial warranty accrual, beginning balance $ 1,359 $ 1,285 $ 1,190 $ 1,706  
Provision for estimated warranty cost 203 190 827 192  
Warranty expenditures (182) (325) (637) (748)  
Initial warranty accrual, ending balance 1,380 1,150 1,380 1,150  
Less warranty accrual, long-term 375 107 375 107 $ 70
Total warranty accrual, current portion $ 1,005 $ 1,043 $ 1,005 $ 1,043 $ 1,120