Defined Contribution Benefit Plan - Additional Information (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Employer matching contributions				$ 0
U.S.
Defined Benefit Plan Disclosure [Line Items]
Employer matching contributions		$ 0	$ 62,000
U.S. | Viventia 401(k) Retirement Plan
Defined Benefit Plan Disclosure [Line Items]
Employer matching contributions	$ 8,000
Canada
Defined Benefit Plan Disclosure [Line Items]
Employer matching contributions	$ 14,000
Employer matching contribution, percent of employees' eligible compensation	4.00%