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	9 Months Ended
	Sep. 30, 2024 USD ($)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ (30,920)
Ending Balance	359,542
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	(9,819)
Reclassification adjustment for (gains) losses included in net income	(3)
Reclassification due to allowance for credit losses recorded during the period	(26)
Impact of net unrealized investment (gains) losses	0
Ending Balance	(7,861)
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	661,777
Reclassification adjustment for (gains) losses included in net income	26,608
Reclassification due to allowance for credit losses recorded during the period	26
Impact of net unrealized investment (gains) losses	0
Ending Balance	(715,769)
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	455,507
Ending Balance	(345,844)
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	(486,539)
Ending Balance	542,559
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	(136,708)
Reclassification adjustment for (gains) losses included in net income	(5,579)
Reclassification due to allowance for credit losses recorded during the period	0
Impact of net unrealized investment (gains) losses	6,519
Ending Balance	110,900
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	515,250
Reclassification adjustment for (gains) losses included in net income	21,026
Reclassification due to allowance for credit losses recorded during the period	0
Impact of net unrealized investment (gains) losses	(24,513)
Ending Balance	$ (416,015)