Revenue from Contracts with Customers (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Disaggregation of Revenue [Line Items]
Total financial services and software subscriptions and services revenue	$ 531	$ 541	$ 1,051	$ 1,079
Revenue from other sources	201	136	394	272
Total fee income and other revenue	732	677	1,445	1,351
Intersegment
Disaggregation of Revenue [Line Items]
Revenue from other sources	36	33	70	66
Retirement Deferred Group and Individual Annuity
Disaggregation of Revenue [Line Items]
Total financial services and software subscriptions and services revenue	163	177	325	353
Retirement Deferred Group and Individual Annuity \| Distribution and shareholder servicing
Disaggregation of Revenue [Line Items]
Total financial services and software subscriptions and services revenue	27	31	54	62
Investment Management [Member]
Disaggregation of Revenue [Line Items]
Total financial services and software subscriptions and services revenue	253	239	493	475
Investment Management [Member] \| Distribution and shareholder servicing
Disaggregation of Revenue [Line Items]
Total financial services and software subscriptions and services revenue	25	32	52	68
Employee Benefits [Member]
Disaggregation of Revenue [Line Items]
Total financial services and software subscriptions and services revenue	12	12	23	20
Benefitfocus
Disaggregation of Revenue [Line Items]
Total financial services and software subscriptions and services revenue	$ 51	$ 50	$ 104	$ 101