XML 64 R53.htm IDEA: XBRL DOCUMENT v3.19.2
Contingencies - Additional Information (Detail) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Jul. 31, 2018
Commitments And Contingencies Disclosure [Abstract]          
Accrued other long-term liabilities $ 4.3   $ 4.3    
Estimated sales and marketing expense $ 0.3 $ 0.3 $ 0.7 $ 0.5  
Freezing amount in cash resulted from court pending legal action issued         $ 2.5