Consolidated Statements Of Shareholders' Equity (USD $) In Thousands, except Share data	Ordinary Shares [Member]	Retained Earnings (Deficit) [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balance, value at Mar. 31, 2009	$ 8,601,934	$ (6,683,317)	$ (57,449)	$ 1,861,168
Balance, shares at Mar. 31, 2009	809,633,000
Exercise of stock options, value	6,026			6,026
Exercise of stock options, shares	2,497,000			2,496,254
Issuance of vested shares under share bonus awards	1,299,000
Net income		18,594		18,594
Stock-based compensation, net of tax	56,735			56,735
Unrealized gain (loss) on derivative instruments and other, net of tax			25,635	25,635
Foreign currency translation			16,409	16,409
Balance, value at Mar. 31, 2010	8,664,695	(6,664,723)	(15,405)	1,984,567
Balance, shares at Mar. 31, 2010	813,429,000
Repurchase of ordinary shares at cost, value	(400,400)			(400,400)
Repurchase of ordinary shares at cost, shares	(65,411,000)
Exercise of stock options, value	23,299			23,299
Exercise of stock options, shares	6,217,000			6,215,867
Issuance of vested shares under share bonus awards	2,759,000
Net income		596,219		596,219
Stock-based compensation, net of tax	54,852			54,852
Unrealized gain (loss) on derivative instruments and other, net of tax			23,276	23,276
Foreign currency translation			12,883	12,883
Balance, value at Mar. 31, 2011	8,342,446	(6,068,504)	20,754	2,294,696
Balance, shares at Mar. 31, 2011	756,994,000			756,993,938
Repurchase of ordinary shares at cost, value	(509,800)			(509,800)
Repurchase of ordinary shares at cost, shares	(81,688,000)
Exercise of stock options, value	23,055			23,055
Exercise of stock options, shares	5,879,000			5,879,405
Issuance of vested shares under share bonus awards	2,555,000
Net income		488,765		488,765
Stock-based compensation, net of tax	48,454			48,454
Unrealized gain (loss) on derivative instruments and other, net of tax			(7,575)	(7,575)
Foreign currency translation			(53,616)	(53,616)
Balance, value at Mar. 31, 2012	$ 7,904,155	$ (5,579,739)	$ (40,437)	$ 2,283,979
Balance, shares at Mar. 31, 2012	683,740,000			683,740,173