v3.26.1
Revenues from Contracts with Customers - Disaggregation within Segments (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Revenues from Contracts with Customers - Disaggregation of Revenues        
Total fees and other revenues $ 1,146.0 $ 1,082.6 $ 2,263.3 $ 2,160.3
Premiums and other considerations 1,460.8 1,396.5 2,608.9 3,147.8
Net investment income 1,301.8 1,162.8 2,500.8 2,328.5
Operating Segments        
Revenues from Contracts with Customers - Disaggregation of Revenues        
Total revenues from contracts with customers 787.0 750.0 1,556.9 1,495.8
Operating Segments | Retirement and Income Solutions        
Revenues from Contracts with Customers - Disaggregation of Revenues        
Total revenues from contracts with customers 181.9 148.2 332.5 293.9
Fees and other revenues not within the scope of revenue recognition guidance 289.0 286.0 588.9 581.5
Total fees and other revenues 470.9 434.2 921.4 875.4
Premiums and other considerations 487.9 447.2 659.8 1,257.5
Net investment income 922.6 836.9 1,819.2 1,660.6
Total operating revenues 1,881.4 1,718.3 3,400.4 3,793.5
Operating Segments | Retirement and Income Solutions | Administrative service fee revenue        
Revenues from Contracts with Customers - Disaggregation of Revenues        
Total revenues from contracts with customers 176.3 143.6 321.4 284.8
Operating Segments | Retirement and Income Solutions | Deposit account fee revenue        
Revenues from Contracts with Customers - Disaggregation of Revenues        
Total revenues from contracts with customers 3.4 3.2 7.0 6.6
Operating Segments | Retirement and Income Solutions | Commission income        
Revenues from Contracts with Customers - Disaggregation of Revenues        
Total revenues from contracts with customers 2.2 1.4 4.1 2.5
Operating Segments | Principal Asset Management        
Revenues from Contracts with Customers - Disaggregation of Revenues        
Total revenues from contracts with customers 526.8 519.6 1,053.9 1,034.3
Operating Segments | Principal Asset Management | Investment Management        
Revenues from Contracts with Customers - Disaggregation of Revenues        
Total revenues from contracts with customers 436.4 433.1 873.2 859.8
Fees and other revenues not within the scope of revenue recognition guidance 13.0 9.8 18.1 12.6
Total fees and other revenues 449.4 442.9 891.3 872.4
Net investment income 22.9 24.3 47.1 48.5
Total operating revenues 472.3 467.2 938.4 920.9
Operating Segments | Principal Asset Management | Investment Management | Management fee revenue        
Revenues from Contracts with Customers - Disaggregation of Revenues        
Total revenues from contracts with customers 396.8 388.1 795.4 777.2
Operating Segments | Principal Asset Management | Investment Management | Other fee revenue        
Revenues from Contracts with Customers - Disaggregation of Revenues        
Total revenues from contracts with customers 39.6 45.0 77.8 82.6
Operating Segments | Principal Asset Management | International Pension        
Revenues from Contracts with Customers - Disaggregation of Revenues        
Total revenues from contracts with customers 96.2 91.4 192.3 183.8
Fees and other revenues not within the scope of revenue recognition guidance 1.0 1.5 2.0 2.7
Total fees and other revenues 97.2 92.9 194.3 186.5
Premiums and other considerations (0.2) 3.9 (0.3) 5.6
Net investment income 228.0 144.0 354.0 286.5
Total operating revenues 325.0 240.8 548.0 478.6
Operating Segments | Principal Asset Management | International Pension | Management fee revenue        
Revenues from Contracts with Customers - Disaggregation of Revenues        
Total revenues from contracts with customers 92.2 87.6 184.5 176.8
Operating Segments | Principal Asset Management | International Pension | Other fee revenue        
Revenues from Contracts with Customers - Disaggregation of Revenues        
Total revenues from contracts with customers 4.0 3.8 7.8 7.0
Operating Segments | Benefits and Protection        
Revenues from Contracts with Customers - Disaggregation of Revenues        
Total revenues from contracts with customers 15.5 26.7 30.8 51.5
Operating Segments | Benefits and Protection | Specialty Benefits        
Revenues from Contracts with Customers - Disaggregation of Revenues        
Total revenues from contracts with customers 3.7 4.0 7.3 7.7
Fees and other revenues not within the scope of revenue recognition guidance 4.2 4.1 8.5 8.7
Total fees and other revenues 7.9 8.1 15.8 16.4
Premiums and other considerations 865.4 832.1 1,718.9 1,655.3
Net investment income 55.6 52.0 111.1 104.4
Total operating revenues 928.9 892.2 1,845.8 1,776.1
Operating Segments | Benefits and Protection | Specialty Benefits | Administrative service fee revenue        
Revenues from Contracts with Customers - Disaggregation of Revenues        
Total revenues from contracts with customers 3.7 4.0 7.3 7.7
Operating Segments | Benefits and Protection | Life Insurance        
Revenues from Contracts with Customers - Disaggregation of Revenues        
Total revenues from contracts with customers 11.8 22.7 23.5 43.8
Fees and other revenues not within the scope of revenue recognition guidance 95.2 91.8 191.8 181.4
Total fees and other revenues 107.0 114.5 215.3 225.2
Premiums and other considerations 117.1 123.5 247.4 247.9
Net investment income 121.0 116.2 219.4 211.6
Total operating revenues 345.1 354.2 682.1 684.7
Operating Segments | Benefits and Protection | Life Insurance | Administrative service fee revenue        
Revenues from Contracts with Customers - Disaggregation of Revenues        
Total revenues from contracts with customers 11.8 10.9 23.5 21.8
Operating Segments | Benefits and Protection | Life Insurance | Commission income        
Revenues from Contracts with Customers - Disaggregation of Revenues        
Total revenues from contracts with customers   11.8   22.0
Operating Segments | Corporate        
Revenues from Contracts with Customers - Disaggregation of Revenues        
Total revenues from contracts with customers 62.8 55.5 139.7 116.1
Fees and other revenues not within the scope of revenue recognition guidance (61.3) (78.1) (138.6) (157.0)
Total fees and other revenues 1.5 (22.6) 1.1 (40.9)
Premiums and other considerations (1.4) (1.4) (2.8) (2.7)
Net investment income 47.6 45.6 109.2 102.3
Total operating revenues 47.7 21.6 107.5 58.7
Operating Segments | Corporate | Commission income        
Revenues from Contracts with Customers - Disaggregation of Revenues        
Total revenues from contracts with customers 117.4 131.9 245.8 263.4
Operating Segments | Corporate | Other fee revenue        
Revenues from Contracts with Customers - Disaggregation of Revenues        
Total revenues from contracts with customers 26.1 25.1 54.0 49.0
Operating Segments | Corporate | Revenue by type - Eliminations        
Revenues from Contracts with Customers - Disaggregation of Revenues        
Total revenues from contracts with customers $ (80.7) $ (101.5) $ (160.1) $ (196.3)