Differentiation between Federal Statutory Tax Rate and Overall Effective Tax Rate (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Tax Rate Reconciliation [Line Items]
Statutory provision	35.00%	35.00%	35.00%	35.00%
State taxes, net of federal benefit	1.10%	0.40%	1.90%	0.50%
City taxes	0.20%	0.10%	0.10%	0.10%
Foreign effective tax rates different from US statutory rate	(9.60%)	(11.30%)	(10.60%)	(12.30%)
Prior Year related state tax payment			0.90%
Valuation Reserve Adjustment			(2.90%)	(2.20%)
Effective Income Tax Rate	26.70%	24.20%	24.40%	21.10%