Consolidated Statement of Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning of period	$ 6,768,161
Other comprehensive gain (loss)	338,745	$ (982,624)	$ (219,781)
End of period	7,469,237	6,768,161
Unrealized investment gains (losses), before tax	47,540	217,311	106,958
Pre-Tax Income (Loss)	1,754,403	1,719,681	1,282,905
Federal and foreign income taxes	(370,557)	(334,727)	(251,890)
Net income	1,383,846	1,384,954	1,031,015
Unrealized investment gains, before tax	392,903	(1,248,128)	(254,939)
Currency translation adjustments, before tax	32,192	1,179
Other comprehensive income (loss), before tax	425,095	(1,246,949)
Unrealized investment gains, tax	(86,350)	264,325
Currency translation adjustments, tax	0	0
Other comprehensive income (loss), tax	(86,350)	264,325
Unrealized investment gains, net of tax	306,553	(983,803)
Change in unrealized translation adjustments	32,192	1,179	(20,969)
Unrealized Investment Gains (Losses)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning of period	(892,905)	90,900
Other comprehensive income before reclassifications	252,782	(1,054,838)
Amounts reclassified from AOCI	53,771	71,035
Other comprehensive gain (loss)	306,553	(983,803)
Unrealized investment loss related to noncontrolling interest	(2)	(2)
End of period	(586,354)	(892,905)	90,900
Unrealized Investment Gains (Losses) | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized investment gains (losses), before tax	68,065	89,918
Federal and foreign income taxes	(14,294)	(18,883)
Net income	53,771	71,035
Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning of period	(371,676)	(372,855)	(351,886)
Other comprehensive income before reclassifications	32,192	1,179
Amounts reclassified from AOCI	0	0
Other comprehensive gain (loss)	32,192	1,179
Unrealized investment loss related to noncontrolling interest	0	0
End of period	(339,484)	(371,676)	(372,855)
Change in unrealized translation adjustments	32,192	1,179	(20,969)
Currency Translation Adjustments | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Pre-Tax Income (Loss)	0	0
Federal and foreign income taxes	0	0
Net income	0	0
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning of period	(1,264,581)	(281,955)
Other comprehensive income before reclassifications	284,974	(1,053,659)
Amounts reclassified from AOCI	53,771	71,035
Other comprehensive gain (loss)	338,745	(982,624)
Unrealized investment loss related to noncontrolling interest	(2)	(2)
End of period	(925,838)	(1,264,581)	$ (281,955)
Accumulated Other Comprehensive Income (Loss) | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Pre-Tax Income (Loss)	68,065	89,918
Federal and foreign income taxes	(14,294)	(18,883)
Net income	$ 53,771	$ 71,035