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, 2025 USD ($)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Begining Balance	$ 4,701,980
Ending Balance	5,468,127
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]
Begining Balance	893
Net investment gains (losses) on investments arising during the period	2,710
Reclassification adjustment for (gains) losses included in net income	310
Reclassification due to allowance for credit losses recorded during the period	6
Impact of net unrealized investment (gains) losses	0
Ending Balance	3,919
Net Unrealized Investment Gains (Losses) on All Other Investments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Begining Balance	(1,847,178)
Net investment gains (losses) on investments arising during the period	325,258
Reclassification adjustment for (gains) losses included in net income	16,582
Reclassification due to allowance for credit losses recorded during the period	(6)
Impact of net unrealized investment (gains) losses	0
Ending Balance	(1,505,344)
Other Costs
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Begining Balance	(583,709)
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	167,546
Ending Balance	(416,163)
Future Policy Benefits and Policyholders’ Account Balances and other liabilities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Begining Balance	920,455
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	(239,370)
Ending Balance	681,085
Income Tax Benefit (Expense)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Begining Balance	316,837
Net investment gains (losses) on investments arising during the period	(68,696)
Reclassification adjustment for (gains) losses included in net income	(3,538)
Reclassification due to allowance for credit losses recorded during the period	0
Impact of net unrealized investment (gains) losses	15,058
Ending Balance	259,661
Accumulated Other Comprehensive Income (Loss) Related To Net Unrealized Investment Gains (Losses)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Begining Balance	(1,192,702)
Net investment gains (losses) on investments arising during the period	259,272
Reclassification adjustment for (gains) losses included in net income	13,354
Reclassification due to allowance for credit losses recorded during the period	0
Impact of net unrealized investment (gains) losses	(56,766)
Ending Balance	$ (976,842)