XML 59 R48.htm IDEA: XBRL DOCUMENT v3.23.2
Accumulated Other Comprehensive Income (Loss) (Schedule of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($)
$ in Millions
 6 Months Ended
Jun. 30, 2023
Jun. 30, 2022
AOCI Attributable to Parent, Net of Tax [Roll Forward]    
Beginning balance $ (89) $ (36)
Ending balance (79) (116)
Pension and Other Post-Retirement Benefits Liability, Net of Tax    
AOCI Attributable to Parent, Net of Tax [Roll Forward]    
Beginning balance 52 20
Net other comprehensive income (loss) attributable to Westlake Corporation (13) 1
Ending balance 39 21
Cumulative Foreign Currency Exchange, Net of Tax    
AOCI Attributable to Parent, Net of Tax [Roll Forward]    
Beginning balance (141) (56)
Net other comprehensive income (loss) attributable to Westlake Corporation 24 (81)
Ending balance (117) (137)
Other, Net of Tax    
AOCI Attributable to Parent, Net of Tax [Roll Forward]    
Beginning balance 0 0
Net other comprehensive income (loss) attributable to Westlake Corporation (1) 0
Ending balance (1) 0
Accumulated Other Comprehensive Loss    
AOCI Attributable to Parent, Net of Tax [Roll Forward]    
Net other comprehensive income (loss) attributable to Westlake Corporation $ 10 $ (80)