FAIR VALUE MEASUREMENTS (Tables)

12 Months Ended

Mar. 31, 2012

Fair Value Disclosures [Abstract]

Fair Value Hierarchy of Financial Assets and Liabilities [Table Text Block]

The following table represents the Company's fair value hierarchy for its financial assets and liabilities:

Fair Values as of March 31, 2012:

(in thousands)	Level 1		Level 2		Total
Cash and cash equivalents:
Cash	$	147,338	$	—	$	147,338
U.S. Treasury Bills	50,000		—		50,000
Commercial Paper	—		11,997		11,997
Short-term investments:
U.S. Treasury Bills and Government Agency Securities	12,898		48,998		61,896
Commercial Paper	—		20,039		20,039
Corporate Bonds	—		38,356		38,356
CDs	—		4,886		4,886
Long-term investments:
U.S. Treasury Bills and Government Agency Securities	6,647		23,190		29,837
Corporate Bonds	—		25,510		25,510
Other current assets:
Derivative assets	—		2,658		2,658
Total assets measured at fair value	$	216,883	$	175,634	$	392,517
Accrued liabilities:
Derivative liabilities	$	7	$	714	$	721

Fair Values as of March 31, 2011:

(in thousands)	Level 1		Level 2		Total
Cash and cash equivalents:
Cash	$	136,804	$	—	$	136,804
U.S. Treasury Bills	74,991		—		74,991
Commercial Paper	—		22,495		22,495
Corporate Bonds	—		3,082		3,082
CDs	—		2,001		2,001
Money Market Accounts	38,000		—		38,000
Short-term investments:
U.S. Treasury Bills and Government Agency Securities	71,756		34,107		105,863
Commercial Paper	—		30,075		30,075
Corporate Bonds	—		11,216		11,216
CDs	—		5,429		5,429
Long-term investments:
U.S. Treasury Bills and Government Agency Securities	7,955		9,436		17,391
Corporate Bonds	—		19,059		19,059
CDs	—		2,882		2,882
Other current assets:
Derivative assets	—		360		360
Total assets measured at fair value	$	329,506	$	140,142	$	469,648
Accrued liabilities:
Derivative liabilities	$	27	$	4,174	$	4,201