Fair Value Measurements (Details) - USD ($) $ in Thousands		Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015
Assets and liabilities measured at fair value on a recurring basis
Cash equivalents		$ 11,578	$ 26,931	$ 8,943
Restricted cash		987	450	941
Commodity derivatives, net	[1]	72,495	11,789	(1,949)
Provisionally price contracts	[2]	(60,708)	(236,990)	(85,086)
Convertible preferred securities	[3]	3,294	13,550	13,300
Other assets and liabilities	[4]	654	5,661	8,966
Total		28,300	(178,609)	(54,885)
Level 1
Assets and liabilities measured at fair value on a recurring basis
Cash equivalents		11,578	26,931	8,943
Restricted cash		987	450	941
Commodity derivatives, net	[1]	48,412	26,890	(6,960)
Provisionally price contracts	[2]	(42,213)	(133,842)	(50,001)
Convertible preferred securities	[3]	0	0	0
Other assets and liabilities	[4]	6,080	8,635	11,531
Total		24,844	(70,936)	(35,546)
Level 2
Assets and liabilities measured at fair value on a recurring basis
Cash equivalents		0	0	0
Restricted cash		0	0	0
Commodity derivatives, net	[1]	24,083	(15,101)	5,011
Provisionally price contracts	[2]	(18,495)	(103,148)	(35,085)
Convertible preferred securities	[3]	0	0	0
Other assets and liabilities	[4]	(5,426)	(3,324)	(2,565)
Total		162	(121,573)	(32,639)
Level 3
Assets and liabilities measured at fair value on a recurring basis
Cash equivalents		0	0	0
Restricted cash		0	0	0
Commodity derivatives, net	[1]	0	0	0
Provisionally price contracts	[2]	0	0	0
Convertible preferred securities	[3]	3,294	13,550	13,300
Other assets and liabilities	[4]	0	350	0
Total		$ 3,294	$ 13,900	$ 13,300

[1] Includes associated cash posted/received as collateral

[2] Recorded in “Other noncurrent assets” on the Company’s Condensed Consolidated Balance Sheets

[3] Recorded in “Other noncurrent assets” on the Company’s Condensed Consolidated Balance Sheets

[4] Included in other assets and liabilities are deferred compensation assets, ethanol risk management contracts, and foreign exchange derivative contracts (Level 1), interest rate derivatives (Level 2), and contingent consideration to the former owners of Kay Flo Industries, Inc (Level 3).