Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Apr. 01, 2018	Dec. 31, 2018
Income Tax [Line Items]
Income tax expense at U.S federal statutory corporate tax rate	21.00%	21.00%
Foreign tax rate differential	9.00%	7.00%
Discrete tax benefit related to stock option exercises	8.00%	13.00%
Increase in reserves for income taxes, net of deferred tax benefit	$ 622
Interest and penalties included in reserve	90
Liability for uncertain tax positions	8,776
Reserve for income taxes classified as a noncurrent iability	7,748		$ 7,106
Reserve for income taxes classified an noncurrent deferred tax assets	1,028
Interest and penalties, gross	940
Minimum decrease in income tax expense due to release in reserves	1,300
Maximum decrease in income tax expense due to release in reserves	$ 1,400
Tax years open to examination by Internal Revenue Service	2015 through 2018
Tax years open to examination by various taxing authorities for other entities	2014 through 2018
Foreign tax authority | Ireland
Income Tax [Line Items]
Income tax expense at U.S federal statutory corporate tax rate	12.50%
Foreign tax authority | China
Income Tax [Line Items]
Income tax expense at U.S federal statutory corporate tax rate	25.00%
Foreign tax authority | Domestic Tax Authority [Member]
Income Tax [Line Items]
Income tax expense at U.S federal statutory corporate tax rate	21.00%