Consolidated Statements of Stockholders' Equity (USD $) In Thousands, unless otherwise specified		Total	Common Stock [Member]	Additional Paid In Capital [Member]	Accumulated Other Comprehensive Income Loss [Member]	Accumulated Deficit [Member]
Balance, beginning of period at Mar. 31, 2012		$ 169,236	$ 619	$ 5,881,336	$ (1,765)	$ (5,710,954)
Balance, shares, beginning of period at Mar. 31, 2012			61,879
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock		22,441	62	22,379
Issuance of common stock, shares			6,199
Repurchase of common stock		(653)	(1)	(652)
Repurchase of common stock, shares			(126)
Stock-based compensation expense	[1]	23,567		23,567
Other comprehensive (loss) gain, net of tax		1,028			1,028
Net loss		(134,115)				(134,115)
Balance, end of period at Mar. 31, 2013		81,504	680	5,926,630	(737)	(5,845,069)
Balance, shares, end of period at Mar. 31, 2013			67,952
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock		62,920	97	62,823
Issuance of common stock, shares			9,725
Stock-based compensation expense	[1]	15,912		15,912
Other comprehensive (loss) gain, net of tax		(5,406)			(5,406)
Net loss		(5,694)				(5,694)
Balance, end of period at Mar. 31, 2014		149,236	777	6,005,365	(6,143)	(5,850,763)
Balance, shares, end of period at Mar. 31, 2014			77,677
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock		7,588	31	7,557
Issuance of common stock, shares			3,139
Stock-based compensation expense	[1]	19,682		19,682
Other comprehensive (loss) gain, net of tax		(1,343)			(1,343)
Net loss		(52,058)				(52,058)
Balance, end of period at Mar. 31, 2015		$ 123,105	$ 808	$ 6,032,604	$ (7,486)	$ (5,902,821)
Balance, shares, end of period at Mar. 31, 2015			80,816

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