Note 4 - Marketable Securities (Detail) - Available-for-sale marketable securities (USD $)	3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Cost basis	$ 255,000
Unrealized gains included in accumulated other comprehensive income	113,000
Fair value	$ 368,000	$ 293,000	[1]

[1] The condensed consolidated balance sheet as of December 31, 2012 has been prepared using information from the audited consolidated balance sheet as of that date.