Investments (Net Investment Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross Investment Income	$ 577,152	$ 387,240	$ 411,900
Less: investment expenses	(26,917)	(19,890)	(18,103)
Net investment income	550,235	367,350	393,797
Equity securities
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross Investment Income	530	410	856
Commercial mortgage and other loans
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross Investment Income	63,548	50,534	57,886
Policy loans
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross Investment Income	69,602	70,363	68,485
Other Invested Assets
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross Investment Income	104,375	36,684	38,577
Short-term investments and cash equivalents
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross Investment Income	712	3,219	9,266
Available-for-sale | Fixed Maturities
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross Investment Income	299,607	224,262	235,456
Trading | Fixed Maturities
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross Investment Income	$ 38,778	$ 1,768	$ 1,374