Income Taxes (Details) $ in Millions	3 Months Ended			12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2020 USD ($) company	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 26, 2020 USD ($)
Components of earnings before income taxes
United States				$ 138	$ 180	$ (82)
Foreign				148	110	93
Total earnings (loss) excluding non-controlling interest				286	290	11
Less: Net loss (income) attributable to noncontrolling interest				0	0	0
Earnings before income taxes				286	290	11
Current:
Federal				(50)	12	(20)
Foreign				35	39	32
State and local				2	(1)
Deferred:
Federal				26	(39)	10
Foreign				(3)	(1)	(5)
State and local				(7)	(7)	(9)
Income tax expense				3	3	8
Unrealized changes in other comprehensive loss				$ (3)	(4)	2
Total income taxes					$ (1)	$ 10
Income taxes
Federal income tax rate (as a percent)				21.00%	21.00%	21.00%
Long-term income tax liability	$ 6	$ 62		$ 6	$ 62
Reconciliation of computed expected tax expense excluding non-controlling interest to income tax expense (benefit) attributable to continuing operations
Computed "expected" tax expense (benefit) excluding non-controlling interest				60	61	$ 2
Adjustments to tax expense (benefit) attributable to:
Foreign tax differences				(4)	14	12
Tax-exempt income				(17)	(29)	(13)
State income taxes, net of federal benefit				(3)	(4)	(6)
Repatriation tax						14	$ 112
Foreign entity tax status change						22
Federal tax credits				(34)	(47)	(23)
Federal rate reduction effect on capital loss carryback						(3)
Other				1	8	3
Income tax expense				3	3	8
Increase in provisional tax impact of the Tax Cuts and Jobs Act						16
Income taxes receivable	18	14		18	14
Income taxes payable	14	16		14	16
Deferred income tax liabilities:
Depreciation	100	119		100	119
Domestic partnerships	59	65		59	65
Unrealized gain on investments	52	36		52	36
Inventory	10	15		10	15
Other	3	4		3	4
Aggregate deferred income tax liabilities	224	239		224	239
Deferred income tax assets:
Reserves/accruals	74	73		74	73
Net operating and capital loss carry-forwards	52	63		52	63
Tax credit carry-forwards	49	75		49	75
Other	5	4		5	4
Aggregate deferred income tax assets	180	215		180	215
Valuation allowance	55	68		55	68
Net deferred income tax liability	$ 99	92		99	92
Time period to recognize tax LIFO reserve as taxable income	4 years
Accrued interest and penalties on uncertain tax positions	$ 8	8		8	8
Unrecognized tax benefits, if recognized, would affect the effective tax rate	30	31		30	31
Reconciliation of the beginning and ending amount of unrecognized tax benefits
Balance at the beginning of the year				31	25
Additions for uncertain tax positions of prior years				2	4
Decreases for uncertain tax positions of prior years	(6)			(7)	(3)
Additions for uncertain tax positions of current year				5	6
Lapse of statute of limitations				(1)	(1)
Balance at the end of the year	30	31		30	31	25
Undistributed earnings from foreign operations	1,300			1,300
Additional tax expense due to change in tax status						22
Expense recorded on IRS audit settlement	6
One-time tax benefit on enactment of law			$ 4
Gross non-taxable revenue related to federal blender's credit		136	61
Other commitments
Contribution to long-term investment				47	38	21
Investment tax credits				$ 22	34
Minimum
Reconciliation of the beginning and ending amount of unrecognized tax benefits
Number of tax years typically subject to examination for major non-US jurisdictions				3 years
Maximum
Reconciliation of the beginning and ending amount of unrecognized tax benefits
Number of tax years typically subject to examination for major non-US jurisdictions				6 years
Allowance for Deferred Tax Assets:
Movement in valuation and qualifying accounts
Balance at beginning of year			$ 59	$ 68	59	59
Charge (credit) to expense				(13)	9
Balance at end of year	55	$ 68		$ 55	68	59	$ 59
Refined coal processing plant
Reconciliation of the beginning and ending amount of unrecognized tax benefits
Number of limited liability companies invested in | company				3
Other commitments
Contribution to long-term investment				$ 17	15	$ 17
Biogas fueled power project
Other commitments
Contribution to long-term investment					$ 20
Tax Period Third Quarter 2020
Deferred income tax assets:
LIFO reserve								$ 51
Foreign
Reconciliation of the beginning and ending amount of unrecognized tax benefits
Net operating loss carry-forwards (NOLs)	111			111
State
Reconciliation of the beginning and ending amount of unrecognized tax benefits
Net operating loss carry-forwards (NOLs)	203			203
Tax credit carry-forwards	$ 22			$ 22