CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating activities:
Net earnings (loss)	$ 4,174	$ (1,165)	$ (630)
Adjustments to reconcile net cash provided by operating activities:
Depreciation, depletion and amortization (Notes 13 and 14)	791	643	616
Gain on sale of Transtar (Note 5)	(506)	0	0
Asset impairment charges (Note 1)	273	263	0
Gain on equity investee transactions (Note 12)	(111)	(31)	0
Restructuring and other charges (Note 25)	128	138	275
Loss on debt extinguishment (Note 7)	292	0	0
Pensions and other post-employment benefits	15	(21)	101
Deferred income taxes (Note 11)	(52)	(130)	202
Net gain on sale of assets	(7)	(149)	(1)
Equity investees (earnings) loss, net of distributions received	(168)	117	(74)
Changes in:
Current receivables	(955)	98	453
Inventories	(677)	506	296
Current accounts payable and accrued expenses	783	(29)	(473)
Income taxes receivable/payable	161	20	13
All other, net	(51)	(122)	(96)
Net cash provided by operating activities	4,090	138	682
Investing activities:
Capital expenditures	(863)	(725)	(1,252)
Acquisition of Big River Steel, net of cash acquired (Note 5)	(625)	0	0
Investment in Big River Steel	0	(9)	(710)
Proceeds from sale of Transtar (Note 5)	627	0	0
Proceeds from sale of assets	26	167	4
Proceeds from sale of ownership interests in equity investees	0	8	0
Other investing activities	(5)	(4)	0
Net cash used in investing activities	(840)	(563)	(1,958)
Financing activities:
Issuance of short-term debt, net of financing costs (Note 17)	0	240	0
Repayment of short-term debt (Note 17)	180	70	0
Revolving credit facilities - borrowings, net of financing costs	50	1,402	860
Revolving credit facilities - repayments	(911)	(1,621)	(100)
Issuance of long-term debt, net of financing costs (Note 17)	864	1,148	702
Repayment of long-term debt (Note 17)	(3,183)	(13)	(155)
Net proceeds from public offering of common stock (Note 27)	790	410	0
Proceeds from Stelco Option Agreement, net of financing costs	0	94	0
Common stock repurchased (Note 27)	(150)	0	(88)
Other financing activities	(27)	(9)	(42)
Net cash (used in) provided by financing activities	(2,747)	1,581	1,177
Effect of exchange rate changes on cash	(21)	23	(2)
Net increase (decrease) in cash, cash equivalents and restricted cash	482	1,179	(101)
Cash, cash equivalents and restricted cash at beginning of year (Note 9)	2,118	939	1,040
Cash, cash equivalents and restricted cash at end of year (Note 9)	$ 2,600	$ 2,118	$ 939