Share-based Compensation (Stock Options Outstanding) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation [Abstract]
Options Outstanding, Units, Beginning Balance	6,437,515	1,685,248
Options Outstanding, Units, Granted	2,853,000	4,858,460
Options Outstanding, Units, Exercised		(1,109)	(772)
Options Outstanding, Units, Forfeited	(793,643)	(105,084)
Options Outstanding, Units, Ending Balance	8,496,872	6,437,515	1,685,248
Options Vested and Exercisable, Units	3,969,407
Options Outstanding, Weighted Average Exercise Price, Beginning Balance	$ 8.32	$ 37.38
Options Outstanding, Weighted Average Exercise Price, Granted	3.69	7.12
Options Outstanding, Weighted Average Exercise Price, Exercised		36.63
Options Outstanding, Weighted Average Exercise Price, Forfeited	6.23	32.09
Options Outstanding, Weighted Average Exercise Price, Ending Balance	6.96	$ 8.32	$ 37.38
Options Vested and Exercisable, Weighted Average Exercise Price	$ 9.76
Options Outstanding, Weighted Average Remaining Contractual Term (years)	8 years 9 months 29 days	9 years 3 months 11 days	8 years 8 months 19 days
Options Vested and Exercisable, Weighted Average Remaining Contractual Term (years)	8 years 15 days
Options Outstanding, Aggregate Intrinsic Value		$ 2,227,268