Revenue (Disaggregation of Revenue from Contracts with Customers) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021
Disaggregation of Revenue [Line Items]
Reportable segment revenues		$ 351	$ 329
Renewals [Member]
Disaggregation of Revenue [Line Items]
Reportable segment revenues		247	224
Real Estate [Member]
Disaggregation of Revenue [Line Items]
Reportable segment revenues	[1]	45	57
Direct-To-Consumer [Member]
Disaggregation of Revenue [Line Items]
Reportable segment revenues	[1]	46	41
Revenue, Other [Member]
Disaggregation of Revenue [Line Items]
Reportable segment revenues		$ 13	$ 8

[1] First-year revenue only.