SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Net Operating Losses
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation allowance, increase (decrease)	$ 219	$ 250	$ 44
Domestic Deferred Tax Assets
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation allowance, increase (decrease)		(11)	208
Foreign Tax Authority
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Income Tax Credits and Adjustments	(105)	(75)	(98)
PT Rio Tinto | Net Operating Losses
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation allowance, increase (decrease)	228
Valuation allowance for deferred tax assets
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	4,732	4,576	4,507
Other Additions (Deductions)	(596)	200	50
Additons Charged to Other Accounts	(49)	(16)	19
SEC Schedule, 12-09, Valuation Allowances and Reserves, Period Increase (Decrease)	0	(28)	0
Balance at End of Year	4,087	4,732	4,576
Reserve for Taxes, Other than Income Taxes
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	82	58	62
Other Additions (Deductions)	18	21	0
SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction	0	(1)	0
SEC Schedule, 12-09, Valuation Allowance and Reserves, Deduction, Other	(41)	4	(4)
Balance at End of Year	$ 59	$ 82	$ 58