Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	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, 2013	$ 81,504	$ 680	$ 5,926,630	$ (737)	$ (5,845,069)
Balance, shares, beginning 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	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	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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock	3,979	$ 38	3,941
Issuance of common stock, shares		3,774
Stock-based compensation expense	22,592		22,592
Other comprehensive (loss) gain, net of tax	(2,067)			(2,067)
Net loss	(32,571)				(32,571)
Balance, end of period at Mar. 31, 2016	$ 115,038	$ 846	$ 6,059,137	$ (9,553)	$ (5,935,392)
Balance, shares, end of period at Mar. 31, 2016		84,590