Income Taxes (Details) $ / shares in Units, $ in Millions		3 Months Ended			12 Months Ended
	Jan. 01, 2018 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2019 USD ($) $ / shares	Mar. 31, 2018 USD ($)	Dec. 31, 2019 USD ($) company	Dec. 31, 2018 USD ($) item	Dec. 31, 2017 USD ($)
2017 Tax Act
Federal income tax rate (as a percent)	21.00%				21.00%	21.00%	35.00%
Number of new U.S. tax base erosion provisions in the 2017 Tax Act | item						2
Long-term income tax liability related to the 2017 Tax Act mandatory deemed repatriated earnings		$ 62	$ 62		$ 62	$ 73
Expected payments on long-term income tax liability in 2021		2	2		2
Expected payments on long-term income tax liability in 2022		6	6		6
Expected payments on long-term income tax liability in 2023		6	6		6
Expected payments on long-term income tax liability in 2024		12	12		12
Expected payments on long-term income tax liability thereafter		36	36		36
Term to repay long-term income tax liability							8 years
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	(3)	$ 150
Adjustments to tax expense (benefit) attributable to:
Foreign tax differences					14	12	(22)
Tax-exempt income					(29)	(13)
State income taxes, net of federal benefit					(4)	(8)	9
Repatriation tax						14	112
Effect on deferreds of federal rate reduction							(47)
Foreign entity tax status change						22
Federal tax credits					(47)	(23)	(18)
Federal rate reduction effect on capital loss carryback						(3)
Domestic manufacturing deduction							(2)
Other					7	3	(1)
Income tax expense					1	1	181
Increase in provisional tax impact of the Tax Cuts and Jobs Act						16
Components of earnings before income taxes
United States					174	(109)	273
Foreign					110	93	155
Total earnings (loss) excluding non-controlling interest					284	(16)	428
Less: Net loss (income) attributable to noncontrolling interest							1
Earnings (loss) before income taxes					284	(16)	427
Current:
Federal					12	(20)	118
Foreign					39	32	19
State and local					(1)		2
Deferred:
Federal					(41)	5	20
Foreign					(1)	(5)	10
State and local					(7)	(11)	12
Income tax expense					1	1	181
Unrealized changes in other comprehensive loss					(4)	2	(3)
Total income taxes					(3)	3	178
Income taxes receivable		14	14		14	39
Income taxes payable		16	16		16	14
Deferred income tax liabilities:
Depreciation		119	119		119	140
Domestic partnerships		65	65		65	78
Unrealized gain on investments		36	36		36
Other		4	4		4	8
Aggregate deferred income tax liabilities		224	224		224	226
Deferred income tax assets:
Reserves/accruals		73	73		73	70
Net operating and capital loss carry-forwards		63	63		63	56
LIFO		2	2		2	7
Tax credit carry-forwards		75	75		75	21
Other		4	4		4	4
Aggregate deferred income tax assets		217	217		217	158
Valuation allowance		68	68		68	59
Net deferred income tax liability		75	75		75	127
Accrued interest and penalties on uncertain tax positions		8	8		8	6
Unrecognized tax benefits, if recognized, would affect the effective tax rate		31	31		31	25
Reconciliation of the beginning and ending amount of unrecognized tax benefits
Balance at the beginning of the year	$ 18			$ 18	25	18
Additions for uncertain tax positions of prior years					4	2
Decreases for uncertain tax positions of prior years					(3)
Additions for uncertain tax positions of current year					6	6
Lapse of statute of limitations					(1)	(1)
Balance at the end of the year		31	31		31	25	18
Undistributed earnings from foreign operations		1,300	$ 1,300		1,300
Additional tax expense due to change in tax status						22
One-time tax benefit on enactment of law				4			0
Gross non-taxable revenue related to federal blender's credit		136		61
Federal blender's credits recognized as revenue per common share | $ / shares			$ 51.14
Other commitments
Contribution to long-term investment					38	21	$ 12
Investment tax credits					$ 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
2017 Tax Act
Federal income tax rate (as a percent)							35.00%
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			$ 59	$ 59	59	$ 58
Charge (credit) to expense					9		1
Balance at end of year		68	$ 68		$ 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					$ 15	$ 17	$ 10
Biogas fueled power project
Reconciliation of the beginning and ending amount of unrecognized tax benefits
Number of limited liability companies invested in | company					2
Other commitments
Contribution to long-term investment					$ 20
Foreign
Reconciliation of the beginning and ending amount of unrecognized tax benefits
Net operating loss carry-forwards (NOLs)		171	171		171
State
Reconciliation of the beginning and ending amount of unrecognized tax benefits
Net operating loss carry-forwards (NOLs)		179	179		179
Tax credit carry-forwards		$ 22	$ 22		$ 22