Summary of Accounting Policies (Weighted-Average Number of Shares Used to Calculate Basic and Diluted Income Per Share) (Details) (USD $)	3 Months Ended								12 Months Ended							12 Months Ended
	Mar. 31, 2011	Dec. 31, 2010	Oct. 01, 2010	Jul. 02, 2010	Mar. 31, 2010	Dec. 31, 2009	Oct. 02, 2009	Jul. 03, 2009	Mar. 31, 2011		Mar. 31, 2010		Mar. 31, 2009		Mar. 31, 2011 1% Convertible Subordinate Notes [Member]	Mar. 31, 2011 Stock Options [Member]	Mar. 31, 2010 Stock Options [Member]	Mar. 31, 2009 Stock Options [Member]	Mar. 31, 2009 Stock Options And Share Bonus Awards [Member]	Jul. 31, 2009 Zero Coupon Convertible Junior Subordinated Notes [Member]	Mar. 31, 2009 Zero Coupon Convertible Junior Subordinated Notes [Member]
Net income (loss)	$ 135,335,000	$ 198,290,000	$ 144,416,000	$ 118,178,000	$ 60,108,000	$ 92,870,000	$ 19,659,000	$ (154,043,000)	$ 596,219,000		$ 18,594,000		$ (6,135,518,000)
Weighted-average ordinary shares outstanding									777,315,000		811,677,000		820,955,000
Basic earnings (loss) per share	$ 0.18	$ 0.26	$ 0.19	$ 0.15	$ 0.07	$ 0.11	$ 0.02	$ (0.19)	$ 0.77		$ 0.02		$ (7.47)
Weighted-average ordinary share equivalents from stock options and awards (1)									12,877,000	[1]	9,435,000	[1]
Weighted-average ordinary share equivalents from convertible notes (2)										[2]		[2]		[2]
Weighted-average shares used in computing per share amounts, Diluted									790,192,000		821,112,000		820,955,000
Diluted earnings (loss) per share	$ 0.17	$ 0.26	$ 0.18	$ 0.14	$ 0.07	$ 0.11	$ 0.02	$ (0.19)	$ 0.75		$ 0.02		$ (7.47)
Share equivalents from options and share bonus awards																25,500,000	38,100,000	61,500,000	1,600,000
1% Convertible subordinated notes									1.00%
Debt instrument, convertible, conversion price															$ 15.525					$ 10.500
Number of shares issued																					0
Additional shares issued for Convertible Notes											0		0

[1] Ordinary share equivalents from stock options to purchase approximately 25.5 million, 38.1 million and 61.5 million shares during fiscal years 2011, 2010 and 2009, respectively, were excluded from the computation of diluted earnings per share primarily because the exercise price of these options was greater than the average market price of the Company's ordinary shares during the respective periods. Additionally, as a result of the company's net loss, ordinary share equivalents from approximately 1.6 million options and share bonus award were excluded from the calculation of diluted earnings (loss) per share during the twelve-month period ended March 31, 2009.

[2] During fiscal year 2011 the Company redeemed its 1% Convertible Subordinated Notes upon maturity. The notes carried conversion provisions to issue shares to settle any conversion spread (excess of the conversion value over the conversion price) in stock. The conversion price was $15.525 per share (subject to certain adjustments). During fiscal years 2010 and 2009, the conversion obligation was less than the principal portion of these notes and accordingly, no additional shares were included as ordinary share equivalents. On July 31, 2009, the principal amount of the Company's Zero Coupon Convertible Junior Subordinated Notes was settled in cash upon maturity. These notes carried conversion provisions to issue shares to settle any conversion spread (excess of the conversion value over the conversion price) in stock. The conversion price was $10.50 per share. On the maturity date the Company's stock price was less than the conversion price, and therefore no shares were issued.