ACCUMULATED OTHER COMPREHENSIVE LOSS - Additional Information (Details) - USD ($) $ in Millions	Sep. 30, 2026	Sep. 30, 2025
Equity [Abstract]
Cumulative income tax expense (benefit) on foreign exchange adjustments	$ 1	$ (7)
Cumulative income tax benefit on pension and postretirement benefit plans	29	26
Cumulative income tax expense on derivatives	$ 0	$ 0

Cumulative Other Comprehensive Income Loss, Pension And Other Postretirement Benefit Plans, Income Tax Expense (Benefit)

No definition available.

Name:	axta_CumulativeOtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansIncomeTaxExpenseBenefit
Namespace Prefix:	axta_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant