Note 8 - Fair Value Measurements (Detail) (USD $)	12 Months Ended						9 Months Ended		9 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Cash And Cash Equivalent [Member]	Dec. 31, 2011 Cash And Cash Equivalent [Member]	Dec. 31, 2012 Marketable Securities [Member]	Dec. 31, 2011 Marketable Securities [Member]	Dec. 31, 2010 Level 3 Non-Financial Assets Measured At Fair Value On A Non-Recurring Basis [Member]	Jan. 01, 2010 Level 3 Non-Financial Assets Measured At Fair Value On A Non-Recurring Basis [Member]	Dec. 31, 2010 Other Long-Lived Assets [Member]
Cash and Cash Equivalents, Fair Value Disclosure			$ 68,200,000	$ 8,500,000	$ 11,900,000	$ 100,000
Debt Instrument, Convertible, Effective Interest Rate	4.00%
Convertible Notes Payable, Current	346,000	346,000
Assets Held-for-sale, Long Lived							6,000,000	10,100,000
Impairment of Long-Lived Assets Held-for-use							$ 4,100,000		$ 6,100,000