Summary of Significant Accounting Policies (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Summary of Significant Accounting Policies [Line Items]
Number of shares excluded from the computation of net loss per share		32,819,830	23,248,254
Foreign currency translation adjustment		$ 9,400		$ 9,100
Cost of government contracts revenue	$ 2,700		$ 5,300
Government Contract Receivable, Unbilled Amounts				900
Reclassified from Other Non-Current Assets to Restricted Cash				900
Restricted Cash and Cash Equivalents, Current		33,312		34,964
Security Deposit [Member]
Summary of Significant Accounting Policies [Line Items]
Restricted Cash and Cash Equivalents, Current		$ 1,700		$ 900
Convertible Debt Securities [Member]
Summary of Significant Accounting Policies [Line Items]
Number of shares excluded from the computation of net loss per share		47,716,900