Acquisitions and Equity Transactions (Details) - USD ($) $ in Thousands			9 Months Ended
	Aug. 19, 2015	Dec. 24, 2014	Sep. 30, 2015	Dec. 31, 2014
Assets (liabilities) acquired:
Goodwill			$ 191,477	$ 188,275
Imperium Renewables, Inc.
Business Acquisition [Line Items]
Cash	$ 36,748
Common stock	15,310
Contingent consideration	5,000
Total	57,058
Assets (liabilities) acquired:
Cash	168
Accounts receivable	8,274
Inventory	18,989
Other current assets	87
Property, plant and equipment	46,476
Intangible assets	2,900
Total identifiable assets acquired	76,894
Accounts payable	(4,828)
Other current liabilities	(942)
Debt	(5,225)
Deferred tax liabilities	3,483
Total liabilities assumed	(14,478)
Net identifiable assets acquired	62,416
Less: Bargain purchase gain	5,358
Non-controlling interest	$ (57,058)
Petrotec AG
Business Acquisition [Line Items]
Cash			$ 4,416
Common stock		$ 20,022
Assets (liabilities) acquired:
Cash		13,523
Accounts receivable		4,989
Inventory		9,470
Other current assets		3,583
Property, plant and equipment		25,026
Total identifiable assets acquired		56,591
Accounts payable		(8,171)
Other current liabilities		(2,151)
Debt		(16,192)
Other noncurrent liabilities		(1,462)
Total liabilities assumed		(27,976)
Net identifiable assets acquired		28,615
Goodwill		369
Non-controlling interest		(8,962)
Net assets acquired		$ 20,022