Unaudited Interim Consolidated Statements of Equity - USD ($) $ in Thousands		Total	Common   Stock	Additional Paid-in Capital	Retained Earnings / (Accumulated Deficit)	Accumulated Other Comprehensive   Income (Loss)
Beginning Balance at Dec. 31, 2021	[1]	$ 6,213,996	$ 2,500	$ 6,042,491	$ (227,449)	$ 396,454
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Contributed capital		8,160		8,160
Comprehensive income (loss):
NET INCOME (LOSS)		(482,207)			(482,207)
Other comprehensive income (loss), net of tax		66,559				66,559
Total comprehensive income (loss)		(415,648)
Ending Balance at Mar. 31, 2022	[1]	5,806,508	2,500	6,050,651	(709,656)	463,013
Beginning Balance at Dec. 31, 2021	[1]	6,213,996	2,500	6,042,491	(227,449)	396,454
Comprehensive income (loss):
NET INCOME (LOSS)	[2]	(1,009,078)
Other comprehensive income (loss), net of tax		(385,457)
Ending Balance at Sep. 30, 2022	[1]	4,811,810	2,500	6,034,840	(1,236,527)	10,997
Beginning Balance at Mar. 31, 2022	[1]	5,806,508	2,500	6,050,651	(709,656)	463,013
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Contributed capital		3,194		3,194
Contributed (distributed) capital-parent/child asset transfers		(13,504)		(13,504)
Comprehensive income (loss):
NET INCOME (LOSS)		(547,018)			(547,018)
Other comprehensive income (loss), net of tax		101,092				101,092
Total comprehensive income (loss)		(445,926)
Ending Balance at Jun. 30, 2022	[1]	5,350,272	2,500	6,040,341	(1,256,674)	564,105
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Contributed capital		6,508		6,508
Contributed (distributed) capital-parent/child asset transfers		(12,009)		(12,009)
Comprehensive income (loss):
NET INCOME (LOSS)		20,147			20,147
Other comprehensive income (loss), net of tax		(553,108)				(553,108)
Total comprehensive income (loss)		(532,961)
Ending Balance at Sep. 30, 2022	[1]	4,811,810	2,500	6,034,840	(1,236,527)	10,997
Beginning Balance at Dec. 31, 2022	[3]	5,036,195	2,500	6,037,914	(994,154)	(10,065)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Contributed capital		405,000		405,000
Contributed (distributed) capital-parent/child asset transfers		1,870		1,870
Comprehensive income (loss):
NET INCOME (LOSS)		279,679			279,679
Other comprehensive income (loss), net of tax		416,704				416,704
Total comprehensive income (loss)		696,383
Ending Balance at Mar. 31, 2023		6,139,448	2,500	6,444,784	(714,475)	406,639
Beginning Balance at Dec. 31, 2022	[3]	5,036,195	2,500	6,037,914	(994,154)	(10,065)
Comprehensive income (loss):
NET INCOME (LOSS)		52,950
Other comprehensive income (loss), net of tax		(729,534)
Ending Balance at Sep. 30, 2023		3,816,917	2,500	5,495,220	(941,204)	(739,599)
Beginning Balance at Mar. 31, 2023		6,139,448	2,500	6,444,784	(714,475)	406,639
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Return of capital		(300,000)		(300,000)
Contributed (distributed) capital-parent/child asset transfers		498		498
Comprehensive income (loss):
NET INCOME (LOSS)		217,598			217,598
Other comprehensive income (loss), net of tax		(386,891)				(386,891)
Total comprehensive income (loss)		(169,293)
Ending Balance at Jun. 30, 2023		5,670,653	2,500	6,145,282	(496,877)	19,748
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Contributed capital		(650,000)		(650,000)
Contributed (distributed) capital-parent/child asset transfers		(62)		(62)
Comprehensive income (loss):
NET INCOME (LOSS)		(444,327)			(444,327)
Other comprehensive income (loss), net of tax		(759,347)				(759,347)
Total comprehensive income (loss)		(1,203,674)
Ending Balance at Sep. 30, 2023		$ 3,816,917	$ 2,500	$ 5,495,220	$ (941,204)	$ (739,599)

[1] Prior period amounts adjusted for the implementation of ASU 2018-12: Targeted Improvements to the Accounting for Long-Duration Contracts.

[2] Prior period amounts adjusted for the implementation of ASU 2018-12: Targeted Improvements to the Accounting for Long-Duration Contracts.

[3]     Prior period amounts adjusted for the implementation of ASU 2018-12: Targeted Improvements to the Accounting for Long-Duration Contracts.