v3.26.1
Business Segments (Financial Information of Company Operating Segments) (Details)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
USD ($)
Jun. 30, 2025
USD ($)
Jun. 30, 2026
USD ($)
segment
Jun. 30, 2025
USD ($)
Segment Reporting [Abstract]        
Number of reportable segments | segment     2  
Number of operating segments | segment     3  
Segment Reporting [Line Items]        
Premiums Earned, Net $ 3,187,389 $ 3,098,185 $ 6,302,561 $ 6,110,566
Investment Income 418,714 379,303 823,048 739,595
Other 110,016 193,320 280,844 368,046
Total revenues 3,716,119 3,670,808 7,406,453 7,218,207
Net Income (Loss) to Common Stockholders 452,261 401,288 967,478 818,860
Net investment gains (55,190) 30,973 (70,965) 47,328
Net investment gains, net of tax (43,335) 24,288 (55,728) 37,115
Income before income taxes 575,198 521,863 1,191,297 1,060,469
Policyholder Benefits and Claims Incurred, Net 1,960,532 1,955,424 3,896,556 3,856,216
Policy Acquisition And Insurance Operating Expenses 909,344 882,099 1,798,528 1,720,345
Other segment amount 271,045 311,422 520,072 581,177
Total 3,140,921 3,148,945 6,215,156 6,157,738
Net investment (losses) gains (55,190) 30,973 (70,965) 47,328
Corporate Reconciling Items And Eliminations        
Segment Reporting [Line Items]        
Investment Income 10,487 (1,031) 35,730 1,583
Other 154,988 152,193 331,750 300,612
Total revenues 165,475 151,162 367,480 302,195
Net Income (Loss) to Common Stockholders (73,593) (116,490) (101,817) (200,710)
Income before income taxes (93,690) (149,081) (129,185) (256,715)
Other segment amount 259,165 300,243 496,665 558,910
Total 259,165 300,243 496,665 558,910
Segment Reporting, Reconciling Item, Corporate Nonsegment        
Segment Reporting [Line Items]        
Income before income taxes (55,190) 30,973 (70,965) 47,328
Net investment (losses) gains (55,190)      
Insurance        
Segment Reporting [Line Items]        
Premiums Earned, Net   2,728,784   5,371,291
Insurance | Operating Segments        
Segment Reporting [Line Items]        
Premiums Earned, Net 2,826,030 2,728,784 5,591,522 5,371,291
Investment Income 337,470 299,476 648,712 590,724
Other 10,218 10,154 20,059 20,106
Total revenues 3,173,718 3,038,414 6,260,293 5,982,121
Net Income (Loss) to Common Stockholders 455,140 393,450 888,607 786,572
Income before income taxes 578,572 512,672 1,103,235 1,022,177
Policyholder Benefits and Claims Incurred, Net 1,782,776 1,742,235 3,549,742 3,429,688
Policy Acquisition And Insurance Operating Expenses 800,490 772,328 1,583,909 1,507,989
Other segment amount 11,880 11,179 23,407 22,267
Total 2,595,146 2,525,742 5,157,058 4,959,944
Insurance | Operating Segments | Non-US        
Segment Reporting [Line Items]        
Total revenues 386,000 361,000 763,000 694,000
Reinsurance & Monoline Excess        
Segment Reporting [Line Items]        
Premiums Earned, Net   369,401   739,275
Reinsurance & Monoline Excess | Operating Segments        
Segment Reporting [Line Items]        
Premiums Earned, Net 361,359 369,401 711,039 739,275
Investment Income 70,757 80,858 138,606 147,288
Other 0 0 0 0
Total revenues 432,116 450,259 849,645 886,563
Net Income (Loss) to Common Stockholders 114,049 100,040 236,416 195,883
Income before income taxes 145,506 127,299 288,212 247,679
Policyholder Benefits and Claims Incurred, Net 177,756 213,189 346,814 426,528
Policy Acquisition And Insurance Operating Expenses 108,854 109,771 214,619 212,356
Total 286,610 322,960 561,433 638,884
Reinsurance & Monoline Excess | Operating Segments | Non-US        
Segment Reporting [Line Items]        
Total revenues $ 118,000 $ 116,000 $ 231,000 $ 246,000