Schedule II - Valuation and Qualifying Accounts

12 Months Ended

Dec. 31, 2021

SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]

Schedule II - Valuation and Qualifying Accounts

Schedule II

Valuation and Qualifying Accounts

For the Years Ended December 31, 2021, 2020 and 2019 

(In millions) Description	Balance at Beginning of Period		Additions Charged to Costs and Expenses		Deductions		Other		Balance at End of Period
Allowance for credit losses - receivables:
2021	$	78	$	3	$	53	$	—	$	28
2020	9		70		16		15		78
2019	8		17		16		—		9
Obsolescence allowance—spare parts:
2021	$	478	$	79	$	11	$	—	$	546
2020	425		88		35		—		478
2019	412		76		63		—		425
Allowance for credit losses - notes receivable:
2021	$	522	$	1	$	—	$	99	$	622
2020	—		518		—		4		522
Valuation allowance for deferred tax assets:
2021	$	247	$	(38)	$	—	$	1	$	210
2020	58		197		8		—		247
2019	59		—		1		—		58