Business Combination - Schedule of Preliminary Purchase Price Consideration (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
	Sep. 20, 2016	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Adjustment			$ (14,600)	$ 0	$ 0
Viventia Bio Inc.
Business Acquisition [Line Items]
Shares Issued			13,525	13,525
Contingent Consideration			31,600	46,200
Adjustment		$ (14,600)
Fair value of consideration transferred	$ 59,700		$ 45,125	$ 59,725