Basis of Presentation and Summary of Significant Accounting Policies (Accounting for Share-Based Compensation) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Basis of Presentation [Line Items]
Share-based compensation expense total	$ 6,045	$ 4,118
Research and development expenses
Basis of Presentation [Line Items]
Share-based compensation expense total	3,939	1,585
General and administrative expenses
Basis of Presentation [Line Items]
Share-based compensation expense total	$ 2,106	$ 2,533