Fair Value Measurements (Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - Recurring - USD ($) $ in Thousands		Dec. 31, 2020	Dec. 31, 2019
Assets and liabilities measured at fair value on a recurring basis
Commodity derivatives, net	[1]	$ 177,467	$ 61,365
Provisionally priced contracts	[2]	(29,025)	(186,651)
Convertible preferred securities	[3]	8,849	8,404
Other assets and liabilities	[4]	(18,086)	(4,038)
Total		139,205	(120,920)
Level 1
Assets and liabilities measured at fair value on a recurring basis
Commodity derivatives, net		51,369	45,682
Provisionally priced contracts		19,793	(118,414)
Convertible preferred securities		0	0
Other assets and liabilities		7,972	9,469
Total		79,134	(63,263)
Level 2
Assets and liabilities measured at fair value on a recurring basis
Commodity derivatives, net		126,098	15,683
Provisionally priced contracts		(48,818)	(68,237)
Convertible preferred securities		0	0
Other assets and liabilities		(26,058)	(13,507)
Total		51,222	(66,061)
Level 3
Assets and liabilities measured at fair value on a recurring basis
Commodity derivatives, net		0	0
Provisionally priced contracts		0	0
Convertible preferred securities		8,849	8,404
Other assets and liabilities		0	0
Total		$ 8,849	$ 8,404

[1] Includes associated cash posted/received as collateral

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

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

[4] 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