Investments (Tables)

9 Months Ended

Sep. 30, 2019

Equity Method Investments And Joint Ventures [Abstract]

Summary of Unaudited Financial Information for Alcoa Corporation's Equity Investments

A summary of unaudited financial information for Alcoa Corporation’s equity investments is as follows (amounts represent 100% of investee financial information):

	Third quarter ended September 30,				Nine months ended September 30,
	2019		2018		2019			2018
Sales	$	1,051	$	1,343	$	3,474		$	3,963
Cost of goods sold		809		1,062		2,789			3,100
Net income (loss)		4		46		(73	)		143