Note 12 - Geographical Information - Revenue by Geographic Areas (Details) - USD ($)	3 Months Ended	6 Months Ended
Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
UNITED STATES
United States, the Company’s country of domicile			$ 64,393,507	$ 63,831,135
Non-US [Member]
United States, the Company’s country of domicile			4,622,736	3,181,314
United States, the Company’s country of domicile	$ 38,522,990	$ 44,653,929	$ 69,016,243	$ 67,012,449

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

Name:	us-gaap_Revenues
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration