Investments (Net Investment Income) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	$ 205,293	$ 100,681	$ 394,963	$ 204,933
Less: investment expenses	(13,165)	(5,381)	(23,535)	(10,766)
Net investment income	192,128	95,300	371,428	194,167
Equity securities
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	1,190	102	1,352	205
Commercial mortgage and other loans
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	22,801	13,322	45,049	26,748
Policy loans
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	5,153	17,315	10,219	34,349
Other invested assets
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	38,243	5,735	75,033	18,808
Short-term investments and cash equivalents
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	3,441	33	4,089	160
Available-for-sale | Fixed maturities
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	121,986	63,630	231,177	123,588
Trading | Fixed maturities
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	$ 12,479	$ 544	$ 28,044	$ 1,075