Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Oct. 03, 2021
Summary Of Significant Accounting Policies [Line Items]
Standard warranty period	12 months
Depreciation over life to cost of revenues and selling and administrative expenses, years	6 years
Net book value of internally manufactured test systems sold	$ 16,600	$ 7,300	$ 5,000
Advertising costs	13,400	12,800	16,600
Losses (gains) on foreign currency transactions	2,100	2,600	$ 1,600
Trade Accounts Receivable	111,300	131,100
Debt Instrument, Face Amount	$ 116,980	459,971
OnePointTwoFivePercentConvertibleSeniorUnsecuredNotesDueDecemberFifteenTwoThousandTwentyThree [Member]
Summary Of Significant Accounting Policies [Line Items]
Debt Instrument, Convertible, Carrying Amount of Equity Component				$ 100,800
Debt Instrument, Face Amount		$ 460,000