v3.26.1
Revenue from Contracts with Customers - Summary of Disaggregation of Revenues from Contracts (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Disaggregation Of Revenue [Line Items]    
Disaggregation of revenues from contracts with customers $ 872,693 $ 804,843
Term Life Insurance Segment [Member]    
Disaggregation Of Revenue [Line Items]    
Disaggregation of revenues from contracts with customers 464,634 457,841
Term Life Insurance Segment [Member] | Total Segment Revenues from Contracts with Customers [Member]    
Disaggregation Of Revenue [Line Items]    
Disaggregation of revenues from contracts with customers 11,275 12,745
Term Life Insurance Segment [Member] | Total Segment Revenues from Contracts with Customers [Member] | Other, Net [Member]    
Disaggregation Of Revenue [Line Items]    
Disaggregation of revenues from contracts with customers 11,275 12,745
Term Life Insurance Segment [Member] | Revenues from Sources Other Than Contracts with Customers (Segregated Funds) [Member]    
Disaggregation Of Revenue [Line Items]    
Disaggregation of revenues from contracts with customers 453,359 445,096
Investment and Savings Products Segment [Member]    
Disaggregation Of Revenue [Line Items]    
Disaggregation of revenues from contracts with customers 350,645 290,812
Investment and Savings Products Segment [Member] | Total Segment Revenues from Contracts with Customers [Member]    
Disaggregation Of Revenue [Line Items]    
Disaggregation of revenues from contracts with customers 337,630 277,928
Investment and Savings Products Segment [Member] | Total Segment Revenues from Contracts with Customers [Member] | Other, Net [Member]    
Disaggregation Of Revenue [Line Items]    
Disaggregation of revenues from contracts with customers 3,305 3,333
Investment and Savings Products Segment [Member] | Total Segment Revenues from Contracts with Customers [Member] | Commissions and Fees [Member] | Sales-based Revenues [Member]    
Disaggregation Of Revenue [Line Items]    
Disaggregation of revenues from contracts with customers 136,355 111,270
Investment and Savings Products Segment [Member] | Total Segment Revenues from Contracts with Customers [Member] | Commissions and Fees [Member] | Asset-based Revenues [Member]    
Disaggregation Of Revenue [Line Items]    
Disaggregation of revenues from contracts with customers 174,351 139,130
Investment and Savings Products Segment [Member] | Total Segment Revenues from Contracts with Customers [Member] | Commissions and Fees [Member] | Account-based Revenues [Member]    
Disaggregation Of Revenue [Line Items]    
Disaggregation of revenues from contracts with customers 23,619 24,195
Investment and Savings Products Segment [Member] | Revenues from Sources Other Than Contracts with Customers (Segregated Funds) [Member]    
Disaggregation Of Revenue [Line Items]    
Disaggregation of revenues from contracts with customers 13,015 12,884
Corporate and Other Distributed Products Segment Revenues [Member]    
Disaggregation Of Revenue [Line Items]    
Disaggregation of revenues from contracts with customers 57,414 56,190
Corporate and Other Distributed Products Segment Revenues [Member] | Total Segment Revenues from Contracts with Customers [Member]    
Disaggregation Of Revenue [Line Items]    
Disaggregation of revenues from contracts with customers 10,707 10,534
Corporate and Other Distributed Products Segment Revenues [Member] | Total Segment Revenues from Contracts with Customers [Member] | Other, Net [Member]    
Disaggregation Of Revenue [Line Items]    
Disaggregation of revenues from contracts with customers 1,306 1,056
Corporate and Other Distributed Products Segment Revenues [Member] | Total Segment Revenues from Contracts with Customers [Member] | Commissions and Fees [Member]    
Disaggregation Of Revenue [Line Items]    
Disaggregation of revenues from contracts with customers 9,401 9,478
Corporate and Other Distributed Products Segment Revenues [Member] | Revenues from Sources Other Than Contracts with Customers (Segregated Funds) [Member]    
Disaggregation Of Revenue [Line Items]    
Disaggregation of revenues from contracts with customers $ 46,707 $ 45,656