Equity (Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Begining Balance	$ 4,701,980
Income tax benefit (expense)	(88,942)	$ 109,279	[1]
Ending Balance	5,468,127
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Begining Balance	(21,941)	(18,085)
Change in OCI before reclassifications	201	(2,362)
Amounts reclassified from AOCI	0	0
Income tax benefit (expense)	(543)	212
Ending Balance	(22,283)	(20,235)
Net unrealized investment gains (losses)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Begining Balance	(1,192,702)	(927,778)
Change in OCI before reclassifications	256,144	(297,240)
Amounts reclassified from AOCI	16,892	(16,067)
Income tax benefit (expense)	(57,176)	65,788
Ending Balance	(976,842)	(1,175,297)
Interest Rate Remeasurement of Future Policy Benefits
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Begining Balance	117,558	71,195
Change in OCI before reclassifications	(12,540)	32,830
Amounts reclassified from AOCI	0	0
Income tax benefit (expense)	2,632	(6,894)
Ending Balance	107,650	97,131
Gain (Loss) from Changes in Non-Performance Risk on Market Risk Benefits
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Begining Balance	495,208	843,707
Change in OCI before reclassifications	161,213	(238,921)
Amounts reclassified from AOCI	0	0
Income tax benefit (expense)	(33,855)	50,173
Ending Balance	622,566	654,959
Accumulated Other Comprehensive   Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Begining Balance	(601,877)	(30,961)
Change in OCI before reclassifications	405,018	(505,693)
Amounts reclassified from AOCI	16,892	(16,067)
Income tax benefit (expense)	(88,942)	109,279
Ending Balance	(268,909)	(443,442)	[2]
Cash flow hedges | Net unrealized investment gains (losses)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Begining Balance	111,000	12,000
Ending Balance	$ 95,000	$ 39,000

[1] Amounts reflect revision to prior period Financial Statements. See Note 16 for additional information.

[2] Amounts reflect revision to prior period Financial Statements. See Note 16 for additional information.