Income Taxes (Components of Income Tax Expense (Benefit)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Current tax expense (benefit):
U.S. federal	$ 440,649	$ (358,548)	$ 56,371
State and local	5,002	0	0
Total	445,651	(358,548)	56,371
Deferred tax expense (benefit):
U.S. federal	(1,137,090)	228,300	(115,503)
Total	(1,137,090)	228,300	(115,503)
Total income tax expense (benefit) on income (loss) before equity in earnings of operating joint ventures	(691,439)	(130,248)	(59,132)
Income tax expense (benefit) on equity in earnings of operating joint ventures	(147)	(518)	(1,773)
Income tax expense (benefit) reported in equity related to:
Other comprehensive income (loss)	(52,374)	70,806	81,281
Total income tax expense (benefit)	$ (743,960)	$ (59,960)	$ 20,376