Segment Information - Reconciliation of Segment Assets to Consolidated (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Segment Information: Assets
Total assets	$ 299,408.2	$ 290,578.3
Retirement and Income Solutions
Segment Information: Assets
Total assets	207,109.0	202,294.2
Principal Asset Management
Segment Information: Assets
Total assets	48,462.3	45,950.7
Benefits and Protection
Segment Information: Assets
Total assets	41,082.2	40,048.3
Corporate
Segment Information: Assets
Total assets	$ 2,754.7	$ 2,285.1