Consolidated Statements of Stockholder's Equity - USD ($) $ in Thousands	Total	Common  Stock	Additional  Paid-in Capital	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment		Accumulated Other   Comprehensive  Income	Total Equity	Total Equity Cumulative Effect, Period of Adoption, Adjustment
Beginning Balance at Dec. 31, 2018		$ 2,500	$ 1,146,592	$ 1,612,435	$ (1,981)	[1]	$ (28,296)	$ 2,733,231	$ (1,981)	[1]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Contributed capital			5,900					5,900
Dividend to parent				(250,000)				(250,000)
Contributed (distributed) capital-parent/child asset transfers			1,140					1,140
Comprehensive income:
Net income (loss)	$ 216,999			216,999				216,999
Other comprehensive income (loss), net of tax	309,738						309,738	309,738
Total comprehensive income (loss)								526,737
Ending Balance at Dec. 31, 2019		2,500	1,153,632	1,577,453	$ (1,752)	[2]	281,442	3,015,027	$ (1,752)	[2]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Contributed capital			575,000					575,000
Contributed (distributed) capital-parent/child asset transfers			(1,942)					(1,942)
Comprehensive income:
Net income (loss)	196,697			196,697				196,697
Other comprehensive income (loss), net of tax	264,686						264,686	264,686
Total comprehensive income (loss)								461,383
Ending Balance at Dec. 31, 2020		2,500	1,726,690	1,772,398			546,128	4,047,716
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Contributed capital			4,342,215					4,342,215
Contributed (distributed) capital-parent/child asset transfers			(26,414)					(26,414)
Comprehensive income:
Net income (loss)	(2,209,730)			(2,209,730)				(2,209,730)
Other comprehensive income (loss), net of tax	$ (198,693)						(198,693)	(198,693)
Total comprehensive income (loss)								(2,408,423)
Ending Balance at Dec. 31, 2021		$ 2,500	$ 6,042,491	$ (437,332)			$ 347,435	$ 5,955,094

[1] Includes the impact from the adoption of ASU 2017-08 and 2017-12.

[2] Includes the impact from the adoption of ASU 2016-13. See Note 2.