Balance Sheet Account Detail - Schedule of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Goodwill [Line Items]
Foreign currency exchange translation effects	$ (336)	$ (235)
Goodwill	18,061	18,162
ZEVALIN Ex-U.S. Distribution Rights [Member]
Goodwill [Line Items]
Acquisition	2,525	2,525
Allos Therapeutics, Inc. [Member]
Goodwill [Line Items]
Acquisition	5,346	5,346
Talon [Member]
Goodwill [Line Items]
Acquisition	$ 10,526	$ 10,526

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

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Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

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