Quarterly report pursuant to Section 13 or 15(d)

SEGMENT INFORMATION (Details)

SEGMENT INFORMATION (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Segment Reporting Information [Line Items]
Net revenues	$ 55,143us-gaap_SalesRevenueNet	$ 64,100us-gaap_SalesRevenueNet
Operating profit before depreciation and amortization	11,974
Operating profit (loss)	9,733us-gaap_OperatingIncomeLoss	4,386us-gaap_OperatingIncomeLoss
Depreciation and amortization	2,241
Capital expenditures	7,743	1,720
Goodwill and intangible assets, net	47,514		47,985
Total assets	235,526us-gaap_Assets		232,074us-gaap_Assets
Product Sales [Member]
Segment Reporting Information [Line Items]
Net revenues	50,541
Processing Fees [Member]
Segment Reporting Information [Line Items]
Net revenues	4,602
Eliminations [Member]
Segment Reporting Information [Line Items]
Goodwill and intangible assets, net	0		0
Total assets	(120,724)		(119,366)
Corporate [Member]
Segment Reporting Information [Line Items]
Net revenues	0
Operating profit before depreciation and amortization	(1,812)
Operating profit (loss)	(1,812)
Depreciation and amortization	0
Goodwill and intangible assets, net	0		0
Total assets	99,575		99,360
Corporate [Member] \| Product Sales [Member]
Segment Reporting Information [Line Items]
Net revenues	0
Corporate [Member] \| Processing Fees [Member]
Segment Reporting Information [Line Items]
Net revenues	0
Petrochemical [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net revenues	48,707
Operating profit before depreciation and amortization	11,712
Operating profit (loss)	10,617
Depreciation and amortization	1,095
Capital expenditures	6,815
Goodwill and intangible assets, net	0		0
Total assets	176,427		172,945
Petrochemical [Member] \| Operating Segments [Member] \| Product Sales [Member]
Segment Reporting Information [Line Items]
Net revenues	47,183
Petrochemical [Member] \| Operating Segments [Member] \| Processing Fees [Member]
Segment Reporting Information [Line Items]
Net revenues	1,524
Specialty Wax [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net revenues	6,436
Operating profit before depreciation and amortization	2,074
Operating profit (loss)	928
Depreciation and amortization	1,146
Capital expenditures	928
Goodwill and intangible assets, net	47,514		47,985
Total assets	80,248		79,135
Specialty Wax [Member] \| Operating Segments [Member] \| Product Sales [Member]
Segment Reporting Information [Line Items]
Net revenues	3,358
Specialty Wax [Member] \| Operating Segments [Member] \| Processing Fees [Member]
Segment Reporting Information [Line Items]
Net revenues	$ 3,078