Reconciliation of Federal Statutory Income Tax Rate to Effective Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Federal statutory rate	35.00%	35.00%	35.00%
State income taxes, net of federal benefit	1.50%	1.50%	1.80%
Domestic manufacturing deduction	(1.10%)	(1.00%)	(1.50%)
Research and development tax credit	(1.10%)	(2.20%)	0.00%
Valuation allowance for foreign subsidiaries net operating losses	0.00%	0.30%	0.00%
Other permanent differences	0.80%	0.10%	(0.40%)
Effective income tax rate for continuing operations	35.10%	33.70%	34.90%