Difference of Income Taxes from Statutory Federal Income Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Reconciliation of Effective Income Tax Rate [Line Items]
Federal U.S. income tax rate	35.00%	35.00%	35.00%
State income taxes, net of federal tax benefit	4.00%	3.40%	2.00%
Non-deductible expenses	0.80%	1.30%	2.70%
Non-U.S. income taxed at different rates, net of foreign tax credits	0.70%	2.20%	3.40%
Federal tax credits	(0.30%)	(1.20%)	(1.30%)
Tax impact of uncertain tax positions	(1.20%)	(0.40%)	0.20%
Other, net		(0.20%)	0.60%
Effective tax rate	39.00%	40.10%	42.60%