v3.22.2
Accumulated Other Comprehensive Income​ (Details) - USD ($)
 3 Months Ended 6 Months Ended
Jun. 30, 2022
Jun. 30, 2021
Jun. 30, 2022
Jun. 30, 2021
AOCI Attributable to Parent [Abstract]        
Balance at beginning of period $ 1,561,000,000 $ 1,490,000,000 $ 1,559,000,000 $ 1,447,000,000
Other comprehensive income:        
Total Other comprehensive income, net of tax 161,000,000 566,000,000 142,000,000 562,000,000
Balance at end of period 1,808,000,000 1,628,000,000 1,808,000,000 1,628,000,000
Restructuring and other charges (E) 2,000,000 597,000,000 7,000,000 598,000,000
Lease cost 14,000,000 14 27,000,000 30
2021 Restructuring Programs        
Other comprehensive income:        
Restructuring and other charges (E)   597,000,000   598,000,000
One-time Termination Benefits | 2021 Restructuring Programs        
Other comprehensive income:        
Restructuring and other charges (E)       568
Pension and other postretirement benefits        
AOCI Attributable to Parent [Abstract]        
Balance at beginning of period (1,063,000,000) (1,766,000,000) (1,121,000,000) (1,791,000,000)
Other comprehensive income:        
Other Comprehensive Income (Loss), before Reclassifications, before Tax 14,000,000 145,000,000 69,000,000 144,000,000
Other Comprehensive Income (Loss) before Reclassifications, Tax (3,000,000) (33,000,000) (15,000,000) (33,000,000)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax 11,000,000 112,000,000 54,000,000 111,000,000
Amortization of net actuarial loss and prior service cost 20,000,000 593,000,000 40,000,000 626,000,000
Tax expense (5,000,000) (138,000,000) (10,000,000) (145,000,000)
Total amount reclassified from Accumulated other comprehensive loss, net of tax 15,000,000 455,000,000 30,000,000 481,000,000
Total Other comprehensive income, net of tax 26,000,000 567,000,000 84,000,000 592,000,000
Balance at end of period (1,037,000,000) (1,199,000,000) (1,037,000,000) (1,199,000,000)
Foreign currency translation        
AOCI Attributable to Parent [Abstract]        
Balance at beginning of period 18,000,000 22,000,000 25,000,000 29,000,000
Other comprehensive income:        
Total Other comprehensive income, net of tax (55,000,000) 13,000,000 (62,000,000) 6,000,000
Balance at end of period (37,000,000) 35,000,000 (37,000,000) 35,000,000
Cash flow hedges        
AOCI Attributable to Parent [Abstract]        
Balance at beginning of period (85,000,000) (21,000,000) (15,000,000) 1,000,000
Other comprehensive income:        
Other Comprehensive Income (Loss), before Reclassifications, before Tax 201,000,000 (59,000,000) 58,000,000 (94,000,000)
Other Comprehensive Income (Loss) before Reclassifications, Tax (46,000,000) 14,000,000 (13,000,000) 22,000,000
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax 155,000,000 (45,000,000) 45,000,000 (72,000,000)
Amortization of net actuarial loss and prior service cost 46,000,000 40,000,000 99,000,000 47,000,000
Tax expense (11,000,000) (9,000,000) (24,000,000) (11,000,000)
Total amount reclassified from Accumulated other comprehensive loss, net of tax 35,000,000 31,000,000 75,000,000 36,000,000
Total Other comprehensive income, net of tax 190,000,000 (14,000,000) 120,000,000 (36,000,000)
Balance at end of period 105,000,000 (35,000,000) 105,000,000 (35,000,000)
Cash flow hedges | Aluminum Contract        
Other comprehensive income:        
Amortization of net actuarial loss and prior service cost (53,000,000) (41,000,000) (106,000,000) (48,000,000)
Cash flow hedges | Energy Related Derivative        
Other comprehensive income:        
Amortization of net actuarial loss and prior service cost 7,000,000 0 7,000,000 0
Cash flow hedges | Commodity Contract        
Other comprehensive income:        
Amortization of net actuarial loss and prior service cost 0 1,000,000 0 1,000,000
Accumulated other comprehensive loss        
AOCI Attributable to Parent [Abstract]        
Balance at beginning of period (1,130,000,000) (1,765,000,000) (1,111,000,000) (1,761,000,000)
Other comprehensive income:        
Total Other comprehensive income, net of tax 161,000,000 566,000,000 142,000,000 562,000,000
Balance at end of period $ (969,000,000) $ (1,199,000,000) $ (969,000,000) $ (1,199,000,000)