Statement of Combined Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Net income (loss)	$ (92)	$ 5	$ (32)	$ 46
Other comprehensive income, net of tax (J):
Change in unrecognized net actuarial loss and prior service benefit related to pension and other postretirement benefits	36	0	61	0
Foreign currency translation adjustments	5	(43)	5	14
Net change in unrecognized losses on cash flow hedges	(7)	0	(7)	0
Total Other comprehensive income, net of tax	34	(43)	59	14
Comprehensive income	(58)	(38)	27	60
Arconic Corporation
Net income (loss)	(92)	5	(32)	46
Other comprehensive income, net of tax (J):
Change in unrecognized net actuarial loss and prior service benefit related to pension and other postretirement benefits	36	0	61	0
Foreign currency translation adjustments	5	(43)	5	14
Net change in unrecognized losses on cash flow hedges	(7)	0	(7)	0
Total Other comprehensive income, net of tax	34	(43)	59	14
Comprehensive income	(58)	(38)	27	60
Noncontrolling interest
Net income (loss)	0	0	0	0
Other comprehensive income, net of tax (J):
Change in unrecognized net actuarial loss and prior service benefit related to pension and other postretirement benefits	0	0	0	0
Foreign currency translation adjustments	0	0	0	0
Net change in unrecognized losses on cash flow hedges	0	0	0	0
Total Other comprehensive income, net of tax	0	0	0	0
Comprehensive income	$ 0	$ 0	$ 0	$ 0