CONDENSED CONSOLIDATED STATEMENTS OF INCOME (PARENTHETICAL) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	$ 13,411		$ 17,134		$ 24,665		$ 25,798
Cost of Sales [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	1,864	[1]	2,614	[1]	3,833	[1]	3,924	[1]
Research and Development Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	6,931		6,358		12,621		10,390
Selling General And Administrative Member
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	$ 6,205		$ 11,581		$ 11,202		$ 16,225

[1] During the three and six months ended September 30, 2013, $2.4 million and $3.8 million, respectively, of share-based compensation expense was capitalized to inventory and $1.9 million and $3.8 million, respectively, of previously capitalized share-based compensation expenses in inventory was sold. During the three and six months ended September 30, 2012, $1.8 million and $3.5 million of share-based compensation expense was capitalized to inventory and $2.6 million and $3.9 million, respectively, of previously capitalized share-based compensation expense in inventory was sold.