LONG-TERM DEBT (Additional Information) (Details)																			3 Months Ended	6 Months Ended			6 Months Ended			3 Months Ended	6 Months Ended						0 Months Ended			0 Months Ended	3 Months Ended				3 Months Ended		6 Months Ended
	Sep. 28, 2011 Second Amended and Restated Credit Agreement [Member] Revolving Credit Facility [Member] Component i [Member] CAD	Sep. 28, 2011 Second Amended and Restated Credit Agreement [Member] Revolving Credit Facility [Member] Component ii [Member] USD ($)	Sep. 28, 2011 Second Amended and Restated Credit Agreement [Member] Seasonal Overadvance Facility [Member] Component i [Member] CAD	Dec. 01, 2011 Second Amended and Restated Credit Agreement [Member] Seasonal Overadvance Facility [Member] Component ii [Member] USD ($)	Sep. 28, 2011 Second Amended and Restated Credit Agreement [Member] Seasonal Overadvance Facility [Member] Component ii [Member] USD ($)	Sep. 28, 2011 Second Amended and Restated Credit Agreement [Member] Swing Line Facility [Member] Component i [Member] CAD	Sep. 28, 2011 Second Amended and Restated Credit Agreement [Member] Swing Line Facility [Member] Component ii [Member] USD ($)	Sep. 30, 2012 Canadian Prime Rate [Member] Second Amended and Restated Credit Agreement [Member]	Sep. 30, 2012 LIBOR [Member] Second Amended and Restated Credit Agreement [Member]	Sep. 30, 2012 US Base Rate [Member] Second Amended and Restated Credit Agreement [Member]	Jun. 30, 2012 Lower Lakes Towing Ltd. [Member] Canadian Prime Rate [Member] Second Amended and Restated Credit Agreement [Member]	Jun. 30, 2012 Lower Lakes Towing Ltd. [Member] Canadian BA Rate [Member] Second Amended and Restated Credit Agreement [Member]	Sep. 28, 2011 Lower Lakes Towing Ltd. [Member] Canadian term loan [Member] Second Amended and Restated Credit Agreement [Member] Secured Debt [Member] CAD	Sep. 28, 2011 Lower Lakes Towing Ltd. [Member] Canadian engine loan [Member] Second Amended and Restated Credit Agreement [Member] Secured Debt [Member] USD ($)	Jun. 30, 2012 Lower Lakes Towing Ltd. [Member] Canadian engine loan [Member] Canadian Prime Rate [Member] Second Amended and Restated Credit Agreement [Member]	Jun. 30, 2012 Lower Lakes Towing Ltd. [Member] Canadian engine loan [Member] Canadian BA Rate [Member] Second Amended and Restated Credit Agreement [Member]	Sep. 30, 2012 Lower Lakes Towing Ltd. [Member] Loans payable [Member] Canadian term loan [Member]	Mar. 31, 2012 Lower Lakes Towing Ltd. [Member] Loans payable [Member] Canadian term loan [Member]	Jun. 30, 2012 Lower Lakes Towing Ltd. [Member] Loans payable [Member] Canadian term loan [Member] Second Amended and Restated Credit Agreement [Member] CAD	Mar. 31, 2012 Lower Lakes Towing Ltd. [Member] Loans payable [Member] Canadian term loan [Member] Second Amended and Restated Credit Agreement [Member] CAD	Mar. 31, 2012 Lower Lakes Towing Ltd. [Member] Loans payable [Member] Canadian term loan [Member] Canadian Prime Rate [Member] Second Amended and Restated Credit Agreement [Member]	Mar. 31, 2012 Lower Lakes Towing Ltd. [Member] Loans payable [Member] Canadian term loan [Member] Canadian BA Rate [Member] Second Amended and Restated Credit Agreement [Member]	Mar. 31, 2012 Lower Lakes Towing Ltd. [Member] Loans payable [Member] US term loan [Member] Second Amended and Restated Credit Agreement [Member] USD ($)	Sep. 30, 2012 Lower Lakes Towing Ltd. [Member] Loans payable [Member] Canadian engine loan [Member]	Mar. 31, 2012 Lower Lakes Towing Ltd. [Member] Loans payable [Member] Canadian engine loan [Member]	Jun. 30, 2012 Lower Lakes Towing Ltd. [Member] Loans payable [Member] Canadian engine loan [Member] Second Amended and Restated Credit Agreement [Member] CAD	Mar. 31, 2012 Lower Lakes Towing Ltd. [Member] Loans payable [Member] Canadian engine loan [Member] Second Amended and Restated Credit Agreement [Member] CAD	Mar. 31, 2012 Lower Lakes Towing Ltd. [Member] Loans payable [Member] Canadian engine loan [Member] Canadian Prime Rate [Member] Second Amended and Restated Credit Agreement [Member]	Sep. 30, 2012 Lower Lakes Towing Ltd. [Member] Loans payable [Member] Canadian engine loan [Member] Canadian BA Rate [Member] Second Amended and Restated Credit Agreement [Member]	Jun. 30, 2012 Grand River Navigation Company, Inc. [Member] LIBOR [Member] Second Amended and Restated Credit Agreement [Member]	Jun. 30, 2012 Grand River Navigation Company, Inc. [Member] US Base Rate [Member] Second Amended and Restated Credit Agreement [Member]	Sep. 28, 2011 Grand River Navigation Company, Inc. [Member] US term loan [Member] Second Amended and Restated Credit Agreement [Member] Secured Debt [Member] USD ($)	Dec. 01, 2011 Grand River Navigation Company, Inc. [Member] Loans payable [Member] US term loan [Member] USD ($)	Sep. 30, 2012 Grand River Navigation Company, Inc. [Member] Loans payable [Member] US term loan [Member]	Mar. 31, 2012 Grand River Navigation Company, Inc. [Member] Loans payable [Member] US term loan [Member]	Dec. 01, 2011 Grand River Navigation Company, Inc. [Member] Loans payable [Member] US term loan [Member] Second Amended and Restated Credit Agreement [Member] USD ($)	Jun. 30, 2012 Grand River Navigation Company, Inc. [Member] Loans payable [Member] US term loan [Member] Second Amended and Restated Credit Agreement [Member] USD ($)	Sep. 30, 2012 Grand River Navigation Company, Inc. [Member] Loans payable [Member] US term loan [Member] LIBOR [Member]	Mar. 31, 2012 Grand River Navigation Company, Inc. [Member] Loans payable [Member] US term loan [Member] LIBOR [Member] Second Amended and Restated Credit Agreement [Member]	Mar. 31, 2012 Grand River Navigation Company, Inc. [Member] Loans payable [Member] US term loan [Member] US Base Rate [Member] Second Amended and Restated Credit Agreement [Member]	Jun. 30, 2012 Black Creek Holdings, Inc. [Member] Loans payable [Member] Black Creek US term loan [Member] USD ($)	Feb. 11, 2011 Black Creek Holdings, Inc. [Member] Loans payable [Member] Black Creek US term loan [Member] USD ($)	Mar. 31, 2012 Black Creek Holdings, Inc. [Member] Loans payable [Member] Black Creek US term loan [Member] Second Amended and Restated Credit Agreement [Member] USD ($)	Jun. 30, 2012 Black Creek Holdings, Inc. [Member] Loans payable [Member] Black Creek US term loan [Member] LIBOR [Member]	Mar. 31, 2012 Black Creek Holdings, Inc. [Member] Loans payable [Member] Black Creek US term loan [Member] LIBOR [Member] Second Amended and Restated Credit Agreement [Member]	Jun. 30, 2012 Black Creek Holdings, Inc. [Member] Loans payable [Member] Black Creek US term loan [Member] US Base Rate [Member]	Sep. 30, 2012 Black Creek Holdings, Inc. [Member] Loans payable [Member] Black Creek US term loan [Member] US Base Rate [Member] Second Amended and Restated Credit Agreement [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Effective Percentage Including Effect of Interest Rate Swap Contracts																	7.23%	6.91%						0.00%	6.28%									6.21%	6.22%
Additional borrowings																																	$ 25,000,000
Basis spread on variable rate								3.50%	4.50%	3.50%	3.50%	4.50%			4.00%	5.00%					3.50%	4.50%						4.00%	5.00%	4.50%	3.50%							4.75%	4.50%	3.50%				4.75%	4.75%	3.75%	3.75%
Authorized amount of line of credit	13,500,000	13,500,000	10,000,000	12,000,000	10,000,000	4,000,000	4,000,000
Face amount													56,133,000	6,267,000																		17,233,000										31,000,000
Quarterly payment																			936,000	936,000			$ 704,000			133,000	133,000									$ 367,000	$ 704,000				$ 517,000		$ 517,000