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Difference Between Provision For Income Taxes And U.S. Federal Statutory Rate (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes
Provision at U.S. federal statutory rate	35.00%	35.00%	35.00%
State taxes, net of federal benefit	1.90%	2.80%	2.60%
U.S. manufacturing credit	(1.40%)	(1.50%)	(1.30%)
Research tax credits	(0.30%)	(0.30%)	(0.30%)
Excess tax benefit on stock compensation	(2.20%)	(1.10%)
Other	0.80%	0.40%	0.30%
Effective Income Tax Rate Continuing Operations Excluding Change in Tax Rate, Total	27.40%	29.40%	29.70%
U.S. Tax Cuts & Jobs Act (U.S. Tax Reform)	15.70%
Effective Income Tax Rate Reconciliation, Percent, Total	43.10%	29.40%	29.70%
State Administration of Taxation, China
Income Taxes
International income tax rate differential	(6.50%)	(6.20%)	(6.80%)
Other
Income Taxes
International income tax rate differential	0.10%	0.30%	0.20%

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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