Statement of Consolidated Comprehensive Income (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Net (loss) income	$ (197)	$ 170
Other comprehensive income, net of tax (C):
Change in unrecognized net actuarial loss and prior service cost/benefit related to pension and other postretirement benefits	77	96
Foreign currency translation adjustments	336	(100)
Net change in unrealized gains on available-for-sale securities		1
Net change in unrecognized losses on derivatives	34	115
Total Other comprehensive income, net of tax	447	112
Comprehensive income	250	282
Alcoa [Member]
Net (loss) income	(178)	149
Other comprehensive income, net of tax (C):
Change in unrecognized net actuarial loss and prior service cost/benefit related to pension and other postretirement benefits	77	95
Foreign currency translation adjustments	249	(116)
Net change in unrealized gains on available-for-sale securities		1
Net change in unrecognized losses on derivatives	32	113
Total Other comprehensive income, net of tax	358	93
Comprehensive income	180	242
Noncontrolling Interests [Member]
Net (loss) income	(19)	21
Other comprehensive income, net of tax (C):
Change in unrecognized net actuarial loss and prior service cost/benefit related to pension and other postretirement benefits		1
Foreign currency translation adjustments	87	16
Net change in unrecognized losses on derivatives	2	2
Total Other comprehensive income, net of tax	89	19
Comprehensive income	$ 70	$ 40