Accounting Policies - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions |
12 Months Ended | ||
---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
Summary Of Significant Accounting Policies [Line Items] | |||
Depreciation over life to cost of revenues and selling and administrative expenses, years | 6 years | ||
Net book value of internally manufactured test systems sold | $ 11.4 | $ 50.7 | $ 9.7 |
Advertising costs | 6.4 | 3.3 | 1.9 |
Gains (losses) on foreign currency transactions | $ 8.0 | $ 2.5 | $ 0.9 |
Convertible Notes | |||
Summary Of Significant Accounting Policies [Line Items] | |||
Initial debt conversion price | $ 5.48 | $ 5.48 | |
Shares that would be issued upon conversion | 34.7 | 34.7 | |
Convertible Notes Hedge Warrant | |||
Summary Of Significant Accounting Policies [Line Items] | |||
Initial debt conversion price | $ 7.67 | $ 7.67 | |
Shares that would be issued upon conversion | 34.7 | 34.7 |