Segment Information - Reportable Segments and Total Assets (Details) $ in Millions	9 Months Ended
	Sep. 30, 2023 USD ($) segment	Dec. 31, 2022 USD ($)		Dec. 31, 2021 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment	4
Summary of assets by segment
Total assets	$ 165,136	$ 158,852	[1]	$ 177,735
Advice & Wealth Management
Summary of assets by segment
Total assets	41,025	35,132
Asset Management
Summary of assets by segment
Total assets	7,124	7,967
Retirement & Protection Solutions
Summary of assets by segment
Total assets	100,609	98,901
Corporate & Other
Summary of assets by segment
Total assets	$ 16,378	$ 16,852

[1] Certain prior period amounts have been restated. See Note 3 for more information.