ACQUISITIONS (Details) (USD $)	3 Months Ended		6 Months Ended		0 Months Ended			0 Months Ended		0 Months Ended
	Jun. 30, 2013	Mar. 31, 2013	Jun. 30, 2013	Jun. 30, 2012	Dec. 28, 2012 Flag Service & Maintenance, Inc. [Member]	Dec. 14, 2012 Penn Maritime Inc. and Maritime Investments LLC [Member] MMBbls	Dec. 14, 2012 Penn Maritime Inc. and Maritime Investments LLC [Member] Tugboats [Member]	Nov. 01, 2012 Allied Transportation Company [Member] bbl	Nov. 01, 2012 Allied Transportation Company [Member] Tank Barges [Member]	Nov. 01, 2012 Allied Transportation Company [Member] Offshore Dry Bulk Barges [Member] T	Nov. 01, 2012 Allied Transportation Company [Member] Coastal Tugboats [Member]
Business acquisition, consideration transferred [Abstract]
Cash consideration paid					$ 6,864,000	$ 146,750,000		$ 107,014,000
Total value of transaction						300,538,000
Stock consideration through issuance of Company common stock						29,080,000
Issue of common stock (in shares)						500,000
Shares issued per share (in dollars per share)						$ 58.16
Number of doubled hulled tank barges						18
Capacity, in barrels, of purchased productive assets (in barrels)						1.9		680,000
Number of productive assets purchased							16		10	3	7
Cash to retire outstanding debt						124,708,000
Capacity, in deadweight tons of purchased productive assets										48,000
Acquisition and integration related costs								10,000,000
Fair value of contingent earnout provision payable in 2014								9,756,000
Payment Of Contingent Liability	$ 5,000,000	$ 5,000,000	$ 5,000,000	$ 0