v3.24.3
Fair Value Measurement (Quantitative Information Regarding Level 3 Valuations) (Details)
$ in Thousands
Sep. 30, 2024
USD ($)
Dec. 31, 2023
USD ($)
Assets:    
Estimated Fair Value $ 3,686,132 $ 3,493,597
Other investments 238,159 245,455
Level 3    
Assets:    
Equity investments 4,489 5,237
Other investments 500 5,126
Liabilities:    
Other liabilities $ 0 6,500
Level 3 | Comparability Adjustment | Discounted Cash Flows | Minimum    
Assets:    
Equity securities measured at fair value 0  
Other investments, measurement input 0  
Level 3 | Comparability Adjustment | Discounted Cash Flows | Maximum    
Assets:    
Equity securities measured at fair value 0.10  
Other investments, measurement input 0.10  
Level 3 | Comparability Adjustment | Discounted Cash Flows | Weighted Average    
Assets:    
Equity securities measured at fair value 0.05  
Other investments, measurement input 0.05  
Level 3 | Weighted Average Cost of Capital | Stochastic Model/Discounted Cash Flows | Minimum    
Liabilities:    
Other liabilities, measurement input 0.00%  
Level 3 | Weighted Average Cost of Capital | Stochastic Model/Discounted Cash Flows | Maximum    
Liabilities:    
Other liabilities, measurement input 10.00%  
Level 3 | Weighted Average Cost of Capital | Stochastic Model/Discounted Cash Flows | Weighted Average    
Liabilities:    
Other liabilities, measurement input 8.00%  
Corporate debt, limited observable inputs | Level 3    
Assets:    
Estimated Fair Value $ 74,808 82,377
Corporate debt, limited observable inputs | Level 3 | Comparability Adjustment | Market Comparable Securities | Minimum    
Assets:    
Assets measured at fair value 0  
Corporate debt, limited observable inputs | Level 3 | Comparability Adjustment | Market Comparable Securities | Maximum    
Assets:    
Assets measured at fair value 0.05  
Corporate debt, limited observable inputs | Level 3 | Comparability Adjustment | Market Comparable Securities | Weighted Average    
Assets:    
Assets measured at fair value 0.025  
Corporate debt, limited observable inputs | Level 3 | Comparability Adjustment | Discounted Cash Flows | Minimum    
Assets:    
Assets measured at fair value 0  
Corporate debt, limited observable inputs | Level 3 | Comparability Adjustment | Discounted Cash Flows | Maximum    
Assets:    
Assets measured at fair value 0.05  
Corporate debt, limited observable inputs | Level 3 | Comparability Adjustment | Discounted Cash Flows | Weighted Average    
Assets:    
Assets measured at fair value 0.025  
Residential mortgage-backed, other commercial mortgage-backed and other asset-backed securities | Level 3    
Assets:    
Estimated Fair Value $ 2,724 $ 4,414
Residential mortgage-backed, other commercial mortgage-backed and other asset-backed securities | Level 3 | Comparability Adjustment | Market Comparable Securities | Minimum    
Assets:    
Assets measured at fair value 0  
Residential mortgage-backed, other commercial mortgage-backed and other asset-backed securities | Level 3 | Comparability Adjustment | Market Comparable Securities | Maximum    
Assets:    
Assets measured at fair value 0.05  
Residential mortgage-backed, other commercial mortgage-backed and other asset-backed securities | Level 3 | Comparability Adjustment | Market Comparable Securities | Weighted Average    
Assets:    
Assets measured at fair value 0.025  
Residential mortgage-backed, other commercial mortgage-backed and other asset-backed securities | Level 3 | Comparability Adjustment | Discounted Cash Flows | Minimum    
Assets:    
Assets measured at fair value 0  
Residential mortgage-backed, other commercial mortgage-backed and other asset-backed securities | Level 3 | Comparability Adjustment | Discounted Cash Flows | Maximum    
Assets:    
Assets measured at fair value 0.05  
Residential mortgage-backed, other commercial mortgage-backed and other asset-backed securities | Level 3 | Comparability Adjustment | Discounted Cash Flows | Weighted Average    
Assets:    
Assets measured at fair value 0.025