Income Taxes (Components of Income Tax Expense (Benefit)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Current tax expense (benefit):
U.S. federal	$ (345,263)	$ 440,649	$ (358,548)
State and local	4,479	5,002	0
Total	(340,784)	445,651	(358,548)
Deferred tax expense (benefit):
U.S. federal	339,902	(1,137,090)	228,300
Total	339,902	(1,137,090)	228,300
Total income tax expense (benefit) on income (loss) before equity in earnings of operating joint ventures	(882)	(691,439)	(130,248)
Income tax expense (benefit) on equity in earnings of operating joint ventures	(193)	(147)	(518)
Income tax expense (benefit) reported in equity related to:
Other comprehensive income (loss)	(510,840)	(52,374)	70,806
Total income tax expense (benefit)	$ (511,915)	$ (743,960)	$ (59,960)