Business And Significant Accounting Policies, Narratives (Details) $ in Thousands			3 Months Ended
	Jan. 01, 2019 USD ($)	Sep. 10, 2018 shares	Mar. 31, 2019 USD ($) item	Dec. 31, 2018 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of Approved Federal Drug Administration Therapies | item			3
Number of product candidate in active clinical development | item			1
Retained Earnings (Accumulated Deficit)			$ (888,454)	$ (880,515)
one-for-10 reverse stock split of common stock		10
Shares of pre-reserve split common stock issued and outstanding | shares		10
Shares of post-reserve split common stock issued and outstanding | shares		1
Impact on Financial Statements, adoption of new accounting standards	$ 10		$ 10
Accounting Standards Update 2016-02 [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Impact on Financial Statements, adoption of new accounting standards	$ 10
Minimum | Accounting Standards Update 2016-02 [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Lease Term			12 months