Income Taxes (Summary of Income Tax Benefit (Provision)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Current:
U.S. Federal	$ 47,761	$ (13,783)
State and local	867	21,114
Foreign	(250)	(250)
Total current	48,378	7,081
Deferred:
U.S. Federal	(9,036)	(80,136)
State and local	6	(53)
Total deferred	(9,030)	(80,189)
Income tax benefit (provision)	$ 39,348	$ (73,108)