Debt - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended					1 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Feb. 10, 2012	Nov. 10, 2011	Mar. 31, 2012 Minimum	Mar. 31, 2012 Maximum	Feb. 10, 2012 Revolving Credit Facility	Nov. 10, 2011 Revolving Credit Facility	Feb. 10, 2012 Term Credit Facility	Nov. 10, 2011 Term Credit Facility	Mar. 31, 2012 Parent Company and Domestic Subsidiaries	Mar. 31, 2012 Foreign Subsidiaries
Debt Instrument [Line Items]
Credit facilities, maximum borrowing capacity								$ 250,000,000		$ 200,000,000
Credit facilities, maturity								5 years		5 years
Note payable under credit facility			370,000,000	75,000,000
Additional borrowing under credit facility							95,000,000		200,000,000
Debt issuance costs			12,300,000
Payment of debt issuance cost	553,000	11,800,000
Credit facility, interest rate description	The applicable margin for borrowings under the Revolving Credit Facility is, based on the calculation of the applicable consolidated total leverage ratio, between 0.50% to 1.50% with respect to base rate borrowings and between 1.50% and 2.50% with respect to LIBOR based borrowings. Interest is due and payable monthly. The interest rate in effect at March 31, 2012 is 2.25%.
Credit facility, interest rate margin above federal fund rate	0.50%
Credit facility, interest rate margin above one-month LIBOR rate	1.00%
Credit facility, interest rate margin above base rate					0.50%	1.50%
Credit facility, interest rate margin above LIBOR rate					1.50%	2.50%
Credit facility, borrowing rate	2.25%
Repayment of term portion of credit agreement	$ 3,125,000
Percentage of capital stock pledged as collateral											100.00%	65.00%