INVESTMENTS IN UNCONSOLIDATED AFFILIATES (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
INVESTMENTS IN UNCONSOLIDATED AFFILIATES
Carrying value of investments in unconsolidated affiliates	$ 229,035,000		$ 211,605,000
Total earnings from unconsolidated affiliates	163,000	40,000
Total additional capital investments in unconsolidated affiliates	18,017,000	56,963,000
Total cash distributions received from unconsolidated affiliates	750,000	178,000
BOSTCO
INVESTMENTS IN UNCONSOLIDATED AFFILIATES
Percentage of ownership	42.50%		42.50%
Storage capacity of storage tanks, the construction of which is involved in the initial phase of acquisition (in barrels)	7,100,000
Estimated construction cost of storage tanks, the construction of which is involved in the initial phase of acquisition	505,000,000
Carrying value of investments in unconsolidated affiliates	203,960,000		186,181,000
Excess investment related to capitalization of interest on investments	4,200,000		3,600,000
Total earnings from unconsolidated affiliates	(80,000)
Total additional capital investments in unconsolidated affiliates	17,972,000	56,897,000
Total cash distributions received from unconsolidated affiliates	113,000
Balance sheets:
Current assets	28,913,000		30,776,000
Long-term assets	489,486,000		458,707,000
Current liabilities	(54,970,000)		(66,469,000)
Net assets	463,429,000		423,014,000
Statements of comprehensive income (loss):
Operating revenue	8,337,000
Operating expenses	(8,455,000)
Net earnings (loss) and comprehensive income (loss)	(118,000)
Frontera
INVESTMENTS IN UNCONSOLIDATED AFFILIATES
Percentage of ownership	50.00%		50.00%
Light petroleum product storage capacity (in barrels)	1,500,000
Carrying value of investments in unconsolidated affiliates	25,075,000		25,424,000
Total earnings from unconsolidated affiliates	243,000	40,000
Total additional capital investments in unconsolidated affiliates	45,000	66,000
Total cash distributions received from unconsolidated affiliates	637,000	178,000
Balance sheets:
Current assets	4,415,000		4,465,000
Long-term assets	46,892,000		47,691,000
Current liabilities	(1,157,000)		(1,308,000)
Net assets	50,150,000		50,848,000
Statements of comprehensive income (loss):
Operating revenue	3,045,000	2,890,000
Operating expenses	(2,559,000)	(2,810,000)
Net earnings (loss) and comprehensive income (loss)	$ 486,000	$ 80,000