Income Taxes (Schedule of Income Tax Benefit (Expense)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
Federal	$ (30)	$ 606	$ 0
State and local	(23)	(24)	0
Current income tax benefit (expense)	(53)	582	0
Deferred:
Federal	(579,378)	192,050	160,150
State and local	(202,183)	(7,757)	(26,628)
Deferred tax benefit (expense)	(781,561)	184,293	133,522
Income tax benefit (expense)	$ (781,614)	$ 184,875	$ 133,522