Properties, Plants, and Equipment, Net (Tables)

12 Months Ended

Dec. 31, 2018

Property Plant And Equipment [Abstract]

Schedule of Properties, Plants, and Equipment, Net

December 31,	2018		2017
Land and land rights, including mines	$	328	$	346
Structures (by type of operation):
Bauxite mining		1,119		1,250
Alumina refining		2,478		2,664
Aluminum smelting and casting		3,532		3,575
Energy generation		506		552
Aluminum rolling		285		298
Other		380		417
		8,300		8,756
Machinery and equipment (by type of operation):
Bauxite mining		480		508
Alumina refining		3,604		4,009
Aluminum smelting and casting		6,489		6,827
Energy generation		889		905
Aluminum rolling		1,029		1,020
Other		282		288
		12,773		13,557
		21,401		22,659
Less: accumulated depreciation, depletion, and amortization		13,480		13,908
		7,921		8,751
Construction work-in-progress		406		387
	$	8,327	$	9,138