New Accounting Standards (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Jan. 01, 2023	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings		$ 6,633,369		$ 6,633,369		$ 6,182,100
Amortized during period		$ (156,129)	$ (151,593)	$ (469,718)	$ (452,607)
Cumulative Effect, Period of Adoption, Adjustment | Minimum | Accounting Standards Update 2018-12 | Forecast
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease in AOCI	$ 7,500,000
Increase in future policy benefits before discount rate change	9,500,000
Increase in future policy benefits	1,200,000
Retained earnings	(15,000)
Amortized during period	120,000
Cumulative Effect, Period of Adoption, Adjustment | Maximum | Accounting Standards Update 2018-12 | Forecast
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease in AOCI	8,500,000
Increase in future policy benefits before discount rate change	11,000,000
Increase in future policy benefits	2,000,000
Retained earnings	(50,000)
Amortized during period	$ 145,000