FAIR VALUE MEASUREMENTS (Tables)

6 Months Ended

Sep. 30, 2011

Fair Value Disclosures [Abstract]

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

The following tables represent the Company’s fair value hierarchy for its financial assets and liabilities:

Fair Values as of September 30, 2011:

(in thousands)	Level 1		Level 2		Level 3		Total
Cash and cash equivalents:
Cash	$	168,875	$	—	$	—	$	168,875
U.S. Treasury Bills and Government Agency Securities	—		5,004		—		5,004
Commercial Paper	—		4,998		—		4,998
Money Market Accounts	6,500		—		—		6,500
Short-term investments:
U.S. Treasury Bills and Government Agency Securities	34,016		27,995		—		62,011
Commercial Paper	—		17,989		—		17,989
Corporate Bonds	—		22,064		—		22,064
CDs	—		2,518		—		2,518
Long-term investments:
U.S. Treasury Bills and Government Agency Securities	—		21,055		—		21,055
Corporate Bonds	—		33,084		—		33,084
CDs	—		4,891		—		4,891
Other current assets:
Derivative assets	—		2,619		—		2,619
Total assets measured at fair value	$	209,391	$	142,217	$	—	$	351,608
Accrued liabilities:
Derivative liabilities	$	23	$	2,292	$	—	$	2,315

Fair Values as of March 31, 2011:

(in thousands)	Level 1		Level 2		Level 3		Total
Cash and cash equivalents:
Cash	$	136,804	$	—	$	—	$	136,804
U.S. Treasury Bills and Government Agency Securities	74,991		7,002		—		81,993
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		27,105		—		98,861
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