CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Balance at Mar. 31, 2010	$ 520,623	$ 840	$ 674,477	$ (150,981)	$ (3,713)
Balance (in shares) at Mar. 31, 2010		83,977,000
Increase (Decrease) in Stockholders' Equity
Net income (loss)	48,458			48,458
Change in cumulative foreign currency translation adjustment	14,172				14,172
Proceeds from exercise of stock options	733	1	732
Proceeds from exercise of stock options (in shares)		65,000
Stock-based compensation	29,293		29,293
Issuance of restricted stock, net of forfeitures and cancellations		18	(18)
Issuance of restricted stock, net of forfeitures and cancellations (in shares)		1,884,000
Issuance of common stock in connection with acquisition	2,000	2	1,998
Issuance of common stock in connection with acquisition (in shares)	192,826	193,000
Balance at Mar. 31, 2011	615,279	861	706,482	(102,523)	10,459
Balance (in shares) at Mar. 31, 2011		86,119,000
Increase (Decrease) in Stockholders' Equity
Net income (loss)	(108,816)			(108,816)
Change in cumulative foreign currency translation adjustment	(3,785)				(3,785)
Proceeds from exercise of stock options	239	1	238
Proceeds from exercise of stock options (in shares)		21,000
Change in unrealized gains on derivative instruments, net	59				59
Stock-based compensation	39,571		39,571
Issuance of 1.75% Convertible Notes	51,180		51,180
Issuance of restricted stock, net of forfeitures and cancellations		39	(39)
Issuance of restricted stock, net of forfeitures and cancellations (in shares)		3,947,000
Issuance of common stock in connection with acquisition	2,000	1	1,999
Issuance of common stock in connection with acquisition (in shares)	128,439	128,000
Balance at Mar. 31, 2012	595,727	902	799,431	(211,339)	6,733
Balance (in shares) at Mar. 31, 2012	90,215,000	90,215,000
Increase (Decrease) in Stockholders' Equity
Net income (loss)	(29,491)			(29,491)
Change in cumulative foreign currency translation adjustment	(11,590)				(11,590)
Change in unrealized gains on derivative instruments, net	285				285
Stock-based compensation	32,664		32,664
Issuance of restricted stock, net of forfeitures and cancellations		35	(35)
Issuance of restricted stock, net of forfeitures and cancellations (in shares)		3,497,000
Issuance of common stock in connection with acquisition	400		400
Issuance of common stock in connection with acquisition (in shares)	30,726	31,000
Balance at Mar. 31, 2013	$ 587,995	$ 937	$ 832,460	$ (240,830)	$ (4,572)
Balance (in shares) at Mar. 31, 2013	93,743,000	93,743,000