BUSINESS COMBINATIONS (Evergreen Oil, Inc) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014 Evergreen Oil, Inc	Sep. 13, 2013 Evergreen Oil, Inc	Dec. 31, 2013 Preliminary Allocations Evergreen Oil, Inc	Mar. 31, 2014 Measurement Period Adjustments Evergreen Oil, Inc
Business Acquisition [Line Items]
Outstanding common shares acquired (as a percent)				100.00%
Summary of recognized assets acquired and liabilities assumed
Inventories and supplies			$ 1,089		$ 1,089	$ 0
Prepaid and other current assets			1,291		1,291	0
Property, plant and equipment			40,563		40,563	0
Permits and other intangibles			17,100		17,100	0
Deferred tax assets, less current portion			2,368		2,368	0
Other assets			3,570		3,607	(37)
Current liabilities			(6,264)		(6,198)	(66)
Closure and post-closure liabilities			(659)		(659)	0
Remedial liabilities, less current portion			(2,000)		(2,103)	103
Other long-term liabilities			(1,139)		(1,139)	0
Total identifiable net assets			55,919		55,919	0
Goodwill	565,062	570,960	0		0	0
Total			$ 55,919		$ 55,919	$ 0