Income Taxes (Summary of Income Tax Benefit (Provision)) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Taxes [Abstract]
Total current income tax (provision) benefit	$ (1,592)	$ (713)	$ (55,581)	$ (2,056)
Total deferred income tax (provision) benefit	(14,960)	(8,198)	(26,655)	(29,010)
Income tax (provision) benefit	$ (16,552)	$ (8,911)	$ (82,236)	$ (31,066)