Presentation Principles of Consolidation (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost		$ 55	$ 56
Disposal Group, Including Discontinued Operation, Assets		36	1,698
Disposal Group, Including Discontinued Operation, Liabilities		$ 0	45
Disposal Group, Including Discontinued Operation, Operating Income (Loss)	$ 4		20
Cash Proceeds from Sale	$ 1,340
Disposal Group, Including Discontinued Operation, Intercompany Assets			2
Disposal Group, Including Discontinued Operation, Intercompany Liabilities			1,274
FORSO [Member]
Restructuring Cost and Reserve [Line Items]
Disposal Group, Including Discontinued Operation, Assets			1,416
Disposal Group, Including Discontinued Operation, Liabilities			$ 45