Reinsurance (Balance Sheet Reinsurance Results) (Details) - USD ($) $ in Thousands	Dec. 31, 2020		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Effects of Reinsurance [Line Items]
Reinsurance recoverables	$ 694,040		$ 621,510
Deferred policy acquisition cost	4,237,780	[1]	4,455,683	$ 4,447,505	$ 4,596,565
Deferred sales inducements	714,598		812,724	889,598	1,020,786
Value of business acquired	27,247		30,025	$ 33,222	$ 35,109
Other assets	767,540		139,933
Policyholders’ account balances	9,181,459		6,180,359
Future policy benefits	18,560,891		12,932,461
Reinsurance payables	178,860		235,318
Other Liabilities	980,692	[1]	447,405
Impacts of Reinsurance
Effects of Reinsurance [Line Items]
Reinsurance recoverables	694,040		621,510
Deferred policy acquisition cost	3,414,620		3,725,719
Deferred sales inducements	374,631		437,594
Value of business acquired	(2,124)		(2,275)
Other assets	61,471		65,819
Policyholders’ account balances	3,273,863		3,253,474
Future policy benefits	12,610,942		8,328,777
Reinsurance payables	178,860		235,318
Other Liabilities	262,462		337,909
Unaffiliated activity
Effects of Reinsurance [Line Items]
Reinsurance payables	$ 2,300		$ 100

[1] December 31, 2020 amounts include the impacts of the January 1, 2020 adoption of ASU 2016-13. See Note 2 for details.