Quarterly report pursuant to Section 13 or 15(d)

ACCUMULATED OTHER COMPREHENSIVE LOSS - Changes in AOCI (loss) related to shareholders' equity (Details)

v3.21.1
ACCUMULATED OTHER COMPREHENSIVE LOSS - Changes in AOCI (loss) related to shareholders' equity (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2021
Mar. 31, 2020
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]    
Beginning balance $ (133) $ (319)
Other comprehensive income (loss) before reclassifications 7 (6)
Net (gain) loss reclassified from accumulated other comprehensive loss 6 8
Ending balance (120) (317)
Postretirement Benefit Liability, net of tax    
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]    
Beginning balance (135) (316)
Other comprehensive income (loss) before reclassifications 0 0
Net (gain) loss reclassified from accumulated other comprehensive loss 7 6
Ending balance (128) (310)
Foreign Currency Translation    
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]    
Beginning balance 3 0
Other comprehensive income (loss) before reclassifications (1) (1)
Net (gain) loss reclassified from accumulated other comprehensive loss 0 0
Ending balance 2 (1)
Derivative Financial Instruments, net of tax    
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]    
Beginning balance (1) (3)
Other comprehensive income (loss) before reclassifications 8 (5)
Net (gain) loss reclassified from accumulated other comprehensive loss (1) 2
Ending balance $ 6 $ (6)