Note 4 - Fair Value - Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Thousands		Dec. 31, 2015	Mar. 31, 2015
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets
Money market funds	[1],[2]	$ 112,307	$ 76,317
Marketable equity securities	[2],[3]	$ 1,785	$ 1,737
Auction rate preferred securities	[2],[3]
Total Assets Measured at Fair Value	[2]	$ 114,092	$ 78,054
Liabilities
Derivative liabilities	[2],[4]
Total Liabilities Measured at Fair Value	[2]
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets
Money market funds	[1],[2]
Marketable equity securities	[2],[3]
Auction rate preferred securities	[2],[3]	$ 350	$ 350
Total Assets Measured at Fair Value	[2]	$ 350	350
Liabilities
Derivative liabilities	[2],[4]		19
Total Liabilities Measured at Fair Value	[2]		19
Fair Value, Measurements, Recurring [Member]
Assets
Money market funds	[1],[2]	$ 112,307	76,317
Marketable equity securities	[2],[3]	1,785	1,737
Auction rate preferred securities	[2],[3]	350	350
Total Assets Measured at Fair Value	[2]	$ 114,442	78,404
Liabilities
Derivative liabilities	[2],[4]		19
Total Liabilities Measured at Fair Value	[2]		19
Marketable equity securities		$ 1,785	1,737
Auction rate preferred securities		$ 350	$ 350

[1] Included in "Cash and cash equivalents" on our unaudited condensed consolidated balance sheets.

[2] We did not have any recurring fair value measurements of assets or liabilities whose fair value was measured using significant unobservable inputs.

[3] Included in "Other assets" on our unaudited condensed consolidated balance sheets.

[4] Included in "Accrued expenses and other current liabilities" on our unaudited condensed consolidated balance sheets.