Income Taxes (Summary of Income Tax Benefit (Provision)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current:
U.S. Federal	$ (1,718)	$ (1,089)	$ (5,524)
State and local	2,981	7,106	3,573
Foreign	(235)	(235)	(220)
Total current	1,028	5,782	(2,171)
Deferred:
U.S. Federal	(26,337)	35,721	8,531
State and local	(3,198)	3,973	1,745
Total deferred	(29,535)	39,694	10,276
Income tax benefit (provision)	$ (28,507)	$ 45,476	$ 8,105