v3.26.1
Revenue from Contracts with Customers - Summary of Disaggregation of Revenues from Contracts (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Disaggregation Of Revenue [Line Items]        
Disaggregation of revenues from contracts with customers $ 865,067 $ 793,334 $ 1,737,759 $ 1,598,177
Term Life Insurance Segment [Member]        
Disaggregation Of Revenue [Line Items]        
Disaggregation of revenues from contracts with customers 443,605 441,834 908,240 899,676
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 11,243 12,221 22,518 24,966
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 11,243 12,221 22,518 24,966
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 432,362 429,613 885,722 874,710
Investment and Savings Products Segment [Member]        
Disaggregation Of Revenue [Line Items]        
Disaggregation of revenues from contracts with customers 360,518 298,298 711,164 589,109
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 347,675 285,374 685,305 563,301
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 3,293 3,236 6,598 6,568
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 135,509 115,933 271,864 227,204
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 184,755 141,811 359,106 280,941
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 24,118 24,394 47,737 48,588
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 12,843 12,924 25,859 25,808
Corporate and Other Distributed Products Segment Revenues [Member]        
Disaggregation Of Revenue [Line Items]        
Disaggregation of revenues from contracts with customers 60,944 53,202 118,355 109,392
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 12,403 11,907 23,109 22,443
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 1,018 937 2,323 1,996
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 11,385 10,970 20,786 20,447
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 $ 48,541 $ 41,295 $ 95,246 $ 86,949