COMMITMENTS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			3 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 Maximum [Member]	Jun. 30, 2012 Operating leases [Member]	Jun. 30, 2011 Operating leases [Member]	Jun. 30, 2012 Operating sublease [Member]	Jun. 30, 2011 Operating sublease [Member]	Jun. 30, 2012 Lower Lakes Towing Ltd. [Member]	Mar. 31, 2012 Lower Lakes Towing Ltd. [Member]
Commitments [Line Items]
Rental payments	$ 142	$ 118		$ 104	$ 81	$ 38	$ 37
Operating Leases, Future Minimum Payments Due, Rolling Maturity [Abstract]
June 30, 2013	360
June 30, 2014	282
June 30, 2015	214
June 30, 2016	150
June 30, 2017	133
Thereafter	113
Total	1,252
Charter costs	249	242
Annual increase of charter costs			3.00%
Operating Leases, Future Minimum Charter Costs Due, Rolling Maturity [Abstract]
June 30, 2013	747
June 30, 2014	747
June 30, 2015	747
June 30, 2016	747
June 30, 2017	747
Thereafter	1,245
Total	4,980
Contractual commitments								$ 3,789	$ 7,143