Long-Term Debt - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	1 Months Ended		12 Months Ended
	Oct. 31, 2012	Nov. 30, 2011 D	Mar. 31, 2013	Nov. 22, 2011	Dec. 31, 2011 Maximum	Dec. 31, 2011 Minimum	Dec. 31, 2011 Federal Funds Effective Rate	Dec. 31, 2011 LIBOR BasisPoint	Dec. 31, 2011 Base Rate Loans Maximum BasisPoint	Dec. 31, 2011 Base Rate Loans Minimum BasisPoint	Dec. 31, 2011 Eurodollar Rate Loans Maximum BasisPoint	Dec. 31, 2011 Eurodollar Rate Loans Minimum BasisPoint	Nov. 22, 2011 Swing Line Loan Sub-Facility Maximum	Nov. 22, 2011 Letter Of Credit Sub-Facility Maximum
Debt Instrument [Line Items]
Payment of outstanding credit facility	$ 62.0
Revolving credit facility outstanding amount				250									10	10
Increase in revolving credit facility outstanding amount				$ 300
Term for increase in revolving credit facility before maturity date, days		90
Line of credit facility, maturity			Nov. 21, 2016
Interest rate in excess of effective rate							0.50%
Margin over applicable interest rate								0.0100	0.0100	0.0025	0.0200	0.0125
Leverage ratio					2.50	1.00
Percentage of capital stock of foreign subsidiaries used as guarantee			65.00%