Equity (Net Unrealized Investment Gains (Losses) in AOCI on AFS Fixed Maturity Securities with Allowance for Credit Losses and All Other Investments) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ (30,920)
Ending Balance	(443,442)
Net Unrealized Investment Gains (Losses) on Available-for-Sale Fixed Maturity Securities on which an allowance for credit losses has been recognized
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	1,987
Net investment gains (losses) on investments arising during the period	(596)
Reclassification adjustment for (gains) losses included in net income	(9)
Reclassification due to allowance for credit losses recorded during the period	(26)
Impact of net unrealized investment (gains) losses	0
Ending Balance	1,356
Net Unrealized Investment Gains (Losses) on All Other Investments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(1,404,180)
Net investment gains (losses) on investments arising during the period	(339,362)
Reclassification adjustment for (gains) losses included in net income	(16,058)
Reclassification due to allowance for credit losses recorded during the period	26
Impact of net unrealized investment (gains) losses	0
Ending Balance	(1,759,574)
Other Costs
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(801,351)
Net investment gains (losses) on investments arising during the period	0
Reclassification adjustment for (gains) losses included in net income	0
Reclassification due to allowance for credit losses recorded during the period	0
Impact of net unrealized investment (gains) losses	(184,494)
Ending Balance	(985,845)
Future Policy Benefits and Policyholders’ Account Balances and other liabilities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	1,029,098
Net investment gains (losses) on investments arising during the period	0
Reclassification adjustment for (gains) losses included in net income	0
Reclassification due to allowance for credit losses recorded during the period	0
Impact of net unrealized investment (gains) losses	227,212
Ending Balance	1,256,310
Income Tax Benefit (Expense)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	246,668
Net investment gains (losses) on investments arising during the period	71,420
Reclassification adjustment for (gains) losses included in net income	3,375
Reclassification due to allowance for credit losses recorded during the period	0
Impact of net unrealized investment (gains) losses	(9,007)
Ending Balance	312,456
Accumulated Other Comprehensive Income (Loss) Related To Net Unrealized Investment Gains (Losses)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(927,778)
Net investment gains (losses) on investments arising during the period	(268,538)
Reclassification adjustment for (gains) losses included in net income	(12,692)
Reclassification due to allowance for credit losses recorded during the period	0
Impact of net unrealized investment (gains) losses	33,711
Ending Balance	$ (1,175,297)