Out-License of MARQIBO, ZEVALIN, & EVOMELA in China Territory - Additional Information (Details) $ in Thousands, shares in Millions		1 Months Ended	12 Months Ended
	Sep. 17, 2014 shares	Sep. 30, 2014 agreement	Dec. 31, 2018 USD ($) shares	Dec. 31, 2017 shares	Dec. 31, 2016 shares	Dec. 31, 2015 USD ($)
Other Commitments [Line Items]
Equity securities (Note 11)			$ 46,422
CASI Out License [Member]
Other Commitments [Line Items]
Number of agreements | agreement		3
Shares received (shares) | shares	5.4			1.5	4.6
Number of shares held in investment (shares) | shares			11.5
Percentage of ownership			12.10%
Equity securities (Note 11)			$ 46,400
Undiscounted proceeds						$ 9,700