CONDENSED CONSOLIDATED STATEMENTS OF INCOME (PARENTHETICAL) - USD ($) $ in Thousands		3 Months Ended
		Jun. 30, 2015	Jun. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense		$ 14,112	$ 13,321
Cost of Sales [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	[1]	1,657	2,055
Research and Development Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense		7,098	6,309
Selling General And Administrative Member
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense		$ 5,357	$ 4,957

[1] During the three months ended June 30, 2015, $1.8 million of share-based compensation expense was capitalized to inventory and $1.7 million of previously capitalized share-based compensation expense in inventory was sold. During the three months ended June 30, 2014, $1.7 million of share-based compensation expense was capitalized to inventory and $2.1 million of previously capitalized share-based compensation expense in inventory was sold.