Major Customers and Geographic Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Net sales by product line
Net sales	$ 6,897	$ 7,242	$ 6,936	$ 6,506	$ 5,986	$ 6,706	$ 5,989	$ 5,950	$ 27,581	$ 24,631	$ 16,827
Major U.S. customer one | Sales | Customer concentration
Net sales by product line
Number of major customers									0	0	0
Concentration risk (as a percent)									10.00%	10.00%	10.00%
Spirulina products
Net sales by product line
Net sales									8,863	8,701	8,387
Natural astaxanthin products BioAstin
Net sales by product line
Net sales									18,713	15,912	8,434
Other products
Net sales by product line
Net sales									$ 5	$ 18	$ 6