Quarterly report pursuant to Section 13 or 15(d)

Basis of Presentation (Additional Information (Detail)

v3.8.0.1
Basis of Presentation (Additional Information (Detail) - Toshiba Japan [Member]
3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Basis Of Presentation [Line Items]    
Engineering Revenues Percentage 94.00% 96.00%
Sales Revenue, Net [Member]    
Basis Of Presentation [Line Items]    
Concentration Risk, Percentage 18.00% 20.00%
Accounts Receivable [Member]    
Basis Of Presentation [Line Items]    
Concentration Risk, Percentage 25.00% 75.00%