Equity (Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	$ 1,533,059
Income tax benefit (expense)	(1,294,005)	$ 865,720	$ 291,101
Ending Balance	169,756	1,533,059
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	(708)	(934)	(1,078)
Change in OCI before reclassifications	(596)	286	182
Amounts reclassified from AOCI	0	0	0
Income tax benefit (expense)	125	(60)	(38)
Ending Balance	(1,179)	(708)	(934)
Net Unrealized Investment Gains (Losses)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	1,533,767	429,546	(323,295)
Change in OCI before reclassifications	(388,886)	1,389,181	956,373
Amounts reclassified from AOCI	(1,336,219)	8,568	(3,123)
Income tax benefit (expense)	362,273	(293,528)	(200,409)
Ending Balance	170,935	1,533,767	429,546
Total Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	1,533,059	428,612	(324,373)
Change in OCI before reclassifications	(389,482)	1,389,467	956,555
Amounts reclassified from AOCI	(1,336,219)	8,568	(3,123)
Income tax benefit (expense)	362,398	(293,588)	(200,447)
Ending Balance	169,756	1,533,059	428,612
Cash flow hedges | Net Unrealized Investment Gains (Losses)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	(43,000)	0
Ending Balance	$ 25,000	$ (43,000)	$ 0