Out-License of ZEVALIN, FOLOTYN, BELEDAQ, and MARQIBO in Canada Territory (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended									12 Months Ended
	Nov. 30, 2018	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Other Significant Noncash Transactions [Line Items]
License fees and service revenue		$ 29,402	$ 25,268	$ 24,168	$ 30,495	$ 28,570	$ 36,395	$ 34,301	$ 29,101		$ 109,333	$ 128,367	$ 146,444
License and Service [Member]
Other Significant Noncash Transactions [Line Items]
License fees and service revenue											$ 4,867	$ 12,189	$ 17,848
License and Service [Member] | ZEVALIN, FOLOTYN, BELEODAQ, And MARQIBO [Member]
Other Significant Noncash Transactions [Line Items]
License fees and service revenue										$ 6,000
License and Service [Member] | FOLOTYN in Canada [Member]
Other Significant Noncash Transactions [Line Items]
License fees and service revenue	$ 1,000