CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2016	Mar. 31, 2015
Statement of Financial Position [Abstract]
Allowance for doubtful accounts receivable	$ 22	$ 27
Unamortized debt issuance costs related to convertible subordinated debt, current	0	390
Unamortized debt issuance costs related to convertible subordinated debt, long-term	$ 747	$ 1,207
Preferred stock, shares authorized	20,000,000	20,000,000
Preferred stock, shares issued	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	266,209,000	258,208,000
Common stock, shares outstanding	266,209,000	258,208,000