Preferred and Common Stock - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended	3 Months Ended	12 Months Ended
	Jan. 31, 2011	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Class of Stock [Line Items]
Common Stock authorized		1,800,000,000	1,800,000,000
Common stock, par value per share		$ 1	$ 1
Common stock issued, in shares		1,177,906,867	1,177,906,867	1,177,906,557
Common stock, dividends yield		$ 0.03	$ 0.12	$ 0.12	$ 0.12
Newly issued common stock, shares	36,518,563
Newly issued common stock, par value	$ 16.43
Newly issued common stock, aggregate value	$ 600
Percentage of funded status of pension plans	80.00%
Number of shares reserved for issuance upon conversion of convertible notes, shares			110,000,000
Number of shares reserved for issuance under Alcoa's stock-based compensation plans, shares			119,000,000
Period of sales and profitability targets to ascertain grant of performance stock awards			3 years	3 years	3 years
Expense related to the acceleration of expense related to retirement-eligible employees			14	13	18
Average period of dividend yield			One-year
Total intrinsic value of options exercised			2	2	34
Cash received from option exercises			13	12	37
Total tax benefit realized from these exercises			1	1	11
Unrecognized compensation costs on non-vested stock option grants (pretax)		16	16
Unrecognized compensation costs on non-vested stock option awards (pretax)		$ 39	$ 39
Unrecognized compensation costs on non-vested awards, weighted average period of recognition in years			1 year 7 months 6 days
Preferred Class A [Member]
Class of Stock [Line Items]
Preferred stock, shares authorized		660,000	660,000
Preferred stock, par value per share		$ 100	$ 100
Cumulative dividend preference per share			$ 3.75
Preferred stock, shares outstanding		546,024	546,024	546,024
Preferred Class B [Member]
Class of Stock [Line Items]
Preferred stock, shares authorized		10,000,000	10,000,000
Preferred stock, par value per share		$ 1	$ 1
Stock Awards [Member]
Class of Stock [Line Items]
Vesting period			Three