Statement of Consolidated Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash from Operations
Net income (loss)	$ 642,000,000	$ (74,000,000)	$ (878,000,000)
Adjustments to reconcile net income (loss) to cash provided from (used for) operations:
Depreciation and amortization	576,000,000	551,000,000	1,132,000,000
Deferred income taxes	31,000,000	434,000,000	1,125,000,000
Equity income, net of dividends	0	0	42,000,000
Impairment of goodwill (A and O)	0	719,000,000	0
Restructuring and other charges	9,000,000	165,000,000	257,000,000
Net loss (gain) from investing activities - asset sales	10,000,000	(513,000,000)	(156,000,000)
Net periodic pension benefit cost (G)	130,000,000	217,000,000	304,000,000
Stock-based compensation	50,000,000	67,000,000	86,000,000
Other	75,000,000	112,000,000	63,000,000
Changes in assets and liabilities, excluding effects of acquisitions, divestitures, and foreign currency translation adjustments:
(Increase) in receivables (A)	(1,142,000,000)	(915,000,000)	(1,016,000,000)
(Increase) in inventories	(74,000,000)	(192,000,000)	(29,000,000)
(Increase) decrease in prepaid expenses and other current assets	(1,000,000)	11,000,000	(76,000,000)
Increase in accounts payable, trade	339,000,000	62,000,000	232,000,000
(Decrease) in accrued expenses	(190,000,000)	(116,000,000)	(394,000,000)
Increase (decrease) in taxes, including income taxes	104,000,000	(23,000,000)	93,000,000
Pension contributions	(298,000,000)	(310,000,000)	(290,000,000)
(Increase) in noncurrent assets	(20,000,000)	(41,000,000)	(152,000,000)
(Decrease) in noncurrent liabilities	(24,000,000)	(193,000,000)	(248,000,000)
Cash provided from (used for) operations	217,000,000	(39,000,000)	95,000,000
Financing Activities
Net change in short-term borrowings (original maturities of three months or less)	(7,000,000)	(2,000,000)	(3,000,000)
Additions to debt (original maturities greater than three months) (P)	600,000,000	816,000,000	1,962,000,000
Payments on debt (original maturities greater than three months) (P)	(1,103,000,000)	(1,634,000,000)	(2,734,000,000)
Premiums paid on early redemption of debt (A and P)	(17,000,000)	(52,000,000)	(3,000,000)
Proceeds from exercise of employee stock options	16,000,000	50,000,000	4,000,000
Dividends paid to shareholders	(119,000,000)	(162,000,000)	(228,000,000)
Distributions to noncontrolling interests	0	(14,000,000)	(226,000,000)
Contributions from noncontrolling interests	0	0	51,000,000
Net cash transferred from Alcoa Corporation at separation	0	0	421,000,000
Other	(19,000,000)	(17,000,000)	(1,000,000)
Cash used for financing activities	(649,000,000)	(1,015,000,000)	(757,000,000)
Investing Activities
Capital expenditures	(768,000,000)	(596,000,000)	(1,125,000,000)
Acquisitions, net of cash acquired (S)	0	0	10,000,000
Proceeds from the sale of assets and businesses (S)	309,000,000	(9,000,000)	692,000,000
Sales of investments (S and V)	9,000,000	890,000,000	280,000,000
Cash receipts from sold receivables (A and L)	1,016,000,000	792,000,000	778,000,000
Other (V)	(1,000,000)	243,000,000	(44,000,000)
Cash provided from investing activities	565,000,000	1,320,000,000	591,000,000
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(4,000,000)	9,000,000	(8,000,000)
Net change in cash, cash equivalents and restricted cash (A)	129,000,000	275,000,000	(79,000,000)
Cash, cash equivalents and restricted cash at beginning of year (A)	2,153,000,000	1,878,000,000	1,957,000,000
Cash, cash equivalents and restricted cash at end of year (A)	$ 2,282,000,000	$ 2,153,000,000	$ 1,878,000,000