Debt - Additional Information (Detail)	12 Months Ended					12 Months Ended						12 Months Ended			1 Months Ended	12 Months Ended
	Mar. 31, 2013 USD ($)	Mar. 31, 2012 USD ($)	Mar. 31, 2011 USD ($)	Mar. 31, 2013 Option Two Libor Rate	Mar. 31, 2013 Option Two Federal Funds Rate	Mar. 31, 2013 2011 Senior Secured Revolving Credit Facility USD ($)	Mar. 31, 2013 2011 Senior Secured Revolving Credit Facility Option One	Mar. 31, 2013 2011 Senior Secured Revolving Credit Facility Option Two	Mar. 31, 2013 Applicable Percentage Option One Libor Rate	Mar. 31, 2013 Applicable Percentage Option Two Libor Rate	Mar. 31, 2013 Secured Debt	Mar. 31, 2013 China Term Loan due 2017 CNY Y	Mar. 31, 2013 India Term Loan due 2017 USD ($)	Mar. 31, 2013 India Term Loan due 2017 INR	May 28, 2008 Convertible Notes Payable USD ($)	Mar. 31, 2013 Convertible Notes Payable USD ($)	Mar. 31, 2012 Convertible Notes Payable USD ($)	Mar. 31, 2011 Convertible Notes Payable USD ($)	Mar. 31, 2013 Senior Unsecured 3.375% Convertible Notes Due 2038 USD ($)	Mar. 31, 2012 Senior Unsecured 3.375% Convertible Notes Due 2038 USD ($)	Mar. 31, 2011 Senior Unsecured 3.375% Convertible Notes Due 2038 USD ($)
Debt Instrument [Line Items]
Senior secured revolving credit facility, initiation date	Mar. 29, 2011
Maximum borrowing capacity						$ 350,000,000						75,000,000		273,780,000
Maturity date						Mar. 31, 2016										Jun. 01, 2038
Liquidity test required to be met	February 2015
Capacity to meet potential obligations related to Convertible Notes	June 2015
Interest on borrowings at a floating rate							("LIBOR") plus an applicable percentage (currently 1.25%)	The greater of the Federal Funds rate plus 0.50% or the prime rate, or one-month LIBOR plus 1.0%, plus an applicable percentage (currently 0.25%)
Interest at a floating rate				1.00%	0.25%				1.25%	0.50%
Interest rate of debt instrument											0.00%					3.375%			3.375%
Company owned capital stock percentage	65.00%
Term loan (in years)												6
Short term borrowing outstanding amount	22,702,000	16,042,000											15,077,000
Face value of debt instrument															172,500,000	172,500,000	172,500,000
Debt instrument maturity year													2017	2017		2038			2038
Net proceeds received after deduction of commissions and offering expenses															168,200,000
Semi-annual payment of interest in arrears																June 1 and December 1
Initial conversion rate																24.6305
Principal amount of Convertible Notes																1,000
Conversion price per share	$ 40.60															$ 40.60
Redemption price percentage of debt instrument of accreted principal amount																100.00%
Minimum price of Common Stock per share for eligibility of make-whole premium payment																$ 29.00
Amortized remaining discount period	26 months
Aggregate consideration on conversion shares	4,248,761
Interest rate percentage																8.50%
Amount of interest cost recognized for the amortization of the discount																7,001,000	6,435,000	5,917,000
Available lines of credit																469,123,000	377,230,000
Outstanding amount																120,373,000	95,340,000
Interest paid																			10,056,000	8,933,000	16,101,000
Short-term debt, weighted-average interest rates	9.00%	9.00%
Stand by letters of credit																11,854,000	9,108,000
Write-off of unamortized deferred financing fees			2,308,000
New deferred financing fees			3,500,000
Deferred financing fees, net of accumulated amortization	3,355,000	4,634,000
Amortization expense included in interest expense	$ 1,279,000	$ 1,278,000	$ 1,861,000