v3.26.1
FAIR VALUE MEASUREMENTS - RECURRING BASIS (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Other invested assets:    
Company-owned life insurance $ 222.3 $ 222.3
Cash and cash equivalents:    
Held by variable interest entities 16.3 27.4
Total assets 39,861.2 38,790.6
Liabilities, Fair Value Disclosure [Abstract]    
Total liabilities 37,269.6 36,152.4
Key Employee    
Other invested assets:    
Company-owned life insurance 211.7 198.6
Total estimated fair value    
Assets:    
Mortgage loans 3,270.8 3,196.9
Policy loans 144.2 140.9
Other invested assets:    
Company-owned life insurance 434.0 420.9
Cash and cash equivalents:    
Unrestricted 1,289.7 956.1
Held by variable interest entities 16.3 27.4
Total assets 5,155.0 4,742.2
Liabilities, Fair Value Disclosure [Abstract]    
Policyholder account balances 17,964.2 17,312.0
Investment borrowings 2,943.6 2,443.2
Borrowings related to variable interest entities 276.6 277.1
Notes payable – direct corporate obligations 1,333.4 1,365.7
Total liabilities 22,517.8 21,398.0
Total carrying amount    
Assets:    
Mortgage loans 3,356.3 3,256.8
Policy loans 144.2 140.9
Other invested assets:    
Company-owned life insurance 434.0 420.9
Cash and cash equivalents:    
Unrestricted 1,289.7 956.1
Held by variable interest entities 16.3 27.4
Total assets 5,240.5 4,802.1
Liabilities, Fair Value Disclosure [Abstract]    
Policyholder account balances 17,964.2 17,312.0
Investment borrowings 2,941.7 2,441.7
Borrowings related to variable interest entities 274.5 274.4
Notes payable – direct corporate obligations 1,336.3 1,335.6
Total liabilities 22,516.7 21,363.7
Quoted prices in active markets for identical assets or liabilities (Level 1)    
Assets:    
Mortgage loans 0.0 0.0
Policy loans 0.0 0.0
Other invested assets:    
Company-owned life insurance 0.0 0.0
Cash and cash equivalents:    
Unrestricted 1,289.7 956.1
Held by variable interest entities 16.3 27.4
Total assets 1,306.0 983.5
Liabilities, Fair Value Disclosure [Abstract]    
Policyholder account balances 0.0 0.0
Investment borrowings 0.0 0.0
Borrowings related to variable interest entities 0.0 0.0
Notes payable – direct corporate obligations 0.0 0.0
Total liabilities 0.0 0.0
Significant other observable inputs (Level 2)    
Assets:    
Mortgage loans 0.0 0.0
Policy loans 0.0 0.0
Other invested assets:    
Company-owned life insurance 434.0 420.9
Cash and cash equivalents:    
Unrestricted 0.0 0.0
Held by variable interest entities 0.0 0.0
Total assets 434.0 420.9
Liabilities, Fair Value Disclosure [Abstract]    
Policyholder account balances 0.0 0.0
Investment borrowings 2,943.6 2,443.2
Borrowings related to variable interest entities 276.6 277.1
Notes payable – direct corporate obligations 1,333.4 1,365.7
Total liabilities 4,553.6 4,086.0
Significant unobservable inputs  (Level 3)    
Assets:    
Mortgage loans 3,270.8 3,196.9
Policy loans 144.2 140.9
Other invested assets:    
Company-owned life insurance 0.0 0.0
Cash and cash equivalents:    
Unrestricted 0.0 0.0
Held by variable interest entities 0.0 0.0
Total assets 3,415.0 3,337.8
Liabilities, Fair Value Disclosure [Abstract]    
Policyholder account balances 17,964.2 17,312.0
Investment borrowings 0.0 0.0
Borrowings related to variable interest entities 0.0 0.0
Notes payable – direct corporate obligations 0.0 0.0
Total liabilities $ 17,964.2 $ 17,312.0