Fair Value Measurements (Assets and Liabilities Measured on Recurring Basis) (Details) - Fair Value, Recurring [Member] - USD ($) $ in Thousands		Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Assets and liabilities measured at fair value on a recurring basis
Commodity derivatives, net	[1]	$ 59,175	$ 61,365	$ 91,590
Provisionally price contracts	[2]	(145,895)	(186,651)	(97,823)
Convertible preferred securities	[3]	8,654	8,404	7,404
Other assets and liabilities	[4]	(27,241)	(4,038)	1,278
Total		(105,307)	(120,920)	2,449
Level 1
Assets and liabilities measured at fair value on a recurring basis
Commodity derivatives, net	[1]	43,832	45,682	60,331
Provisionally price contracts	[2]	(94,834)	(118,414)	(48,430)
Convertible preferred securities	[3]	0	0	0
Other assets and liabilities	[4]	5,373	9,469	5,772
Total		(45,629)	(63,263)	17,673
Level 2
Assets and liabilities measured at fair value on a recurring basis
Commodity derivatives, net	[1]	15,343	15,683	31,259
Provisionally price contracts	[2]	(51,061)	(68,237)	(49,393)
Convertible preferred securities	[3]	0	0	0
Other assets and liabilities	[4]	(32,614)	(13,507)	(4,494)
Total		(68,332)	(66,061)	(22,628)
Level 3
Assets and liabilities measured at fair value on a recurring basis
Commodity derivatives, net	[1]	0	0	0
Provisionally price contracts	[2]	0	0	0
Convertible preferred securities	[3]	8,654	8,404	7,404
Other assets and liabilities	[4]	0	0	0
Total		$ 8,654	$ 8,404	$ 7,404

[1] (a) Includes associated cash posted/received as collateral

[2] (b) Included in "Provisionally priced contracts" are those instruments based only on underlying futures values (Level 1) and delayed price contracts (Level 2)

[3] (c) Recorded in “Other assets, net” on the Company’s Consolidated Balance Sheets related to certain available for sale securities.

[4] (d) Included in other assets and liabilities are assets held by the Company to fund deferred compensation plans, ethanol risk management contracts, and foreign exchange derivative contracts (Level 1) and interest rate derivatives (Level 2).