Basis Of Presentation Financial Instruments - Fair Value Measurements (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2025	Dec. 31, 2024
Fair Value, Liabilities Rollforward [Roll Forward]
Fair value of contingent consideration at December 31, 2024	$ 2
Additions: contingent consideration related to acquisitions completed during the period	0
Reductions: payments of contingent consideration	0
Changes in fair value (reflected in general and administrative expenses)	0
Fair value of contingent consideration at September 30, 2025	2
Fair Value, Measurements, Recurring \| Deferred Compensation Plan Assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred compensation plan assets (included in other non-current assets)	1	$ 1
Fair Value, Measurements, Recurring \| Deferred Compensation Plan Assets \| Level I
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred compensation plan assets (included in other non-current assets)	1	1
Fair Value, Measurements, Recurring \| Deferred Compensation Plan Assets \| Level II
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred compensation plan assets (included in other non-current assets)	0	0
Fair Value, Measurements, Recurring \| Deferred Compensation Plan Assets \| Level III
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred compensation plan assets (included in other non-current assets)	0	0
Fair Value, Measurements, Recurring \| Contingent Consideration for Acquisitions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration for acquisitions (included in accrued expenses and other current liabilities and other non-current liabilities)	2	2
Fair Value, Measurements, Recurring \| Contingent Consideration for Acquisitions \| Level I
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration for acquisitions (included in accrued expenses and other current liabilities and other non-current liabilities)	0	0
Fair Value, Measurements, Recurring \| Contingent Consideration for Acquisitions \| Level II
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration for acquisitions (included in accrued expenses and other current liabilities and other non-current liabilities)	0	0
Fair Value, Measurements, Recurring \| Contingent Consideration for Acquisitions \| Level III
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration for acquisitions (included in accrued expenses and other current liabilities and other non-current liabilities)	$ 2	$ 2

Anywhere Real Estate Inc. 10-Q