Equity (Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024		Sep. 30, 2025	Sep. 30, 2024
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Begining Balance				$ 4,701,980
Income tax benefit (expense)	$ (25,864)	$ (229,226)	[1]	(185,674)	$ (105,677)	[1]
Ending Balance	6,187,825			6,187,825
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Begining Balance				(21,941)	(18,085)
Change in OCI before reclassifications				3,392	1,578
Amounts reclassified from AOCI				0	0
Income tax benefit (expense)				(1,285)	(228)
Ending Balance	(19,834)	(16,735)		(19,834)	(16,735)
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				936,698	620,926
Amounts reclassified from AOCI				78,511	37,481
Income tax benefit (expense)				(213,034)	(138,052)
Ending Balance	(390,527)	(407,423)		(390,527)	(407,423)
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				(51,770)	(21,655)
Amounts reclassified from AOCI				0	0
Income tax benefit (expense)				10,871	4,557
Ending Balance	76,659	54,097		76,659	54,097
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				(84,639)	(133,558)
Amounts reclassified from AOCI				0	0
Income tax benefit (expense)				17,774	28,046
Ending Balance	428,343	738,195		428,343	738,195
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Begining Balance	(1,344)	(498,247)		(601,877)	(30,961)
Change in OCI before reclassifications				803,681	467,291
Amounts reclassified from AOCI				78,511	37,481
Income tax benefit (expense)				(185,674)	(105,677)
Ending Balance	94,641	368,134	[2]	94,641	368,134	[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	$ (131,000)	$ 2,000		$ (131,000)	$ 2,000

[1] Amounts reflect revision to prior period Financial Statements. See Note 17 for additional information.

[2] Amounts reflect revision to prior period Financial Statements. See Note 17 for additional information.