Restructuring Charges - Narrative (Details)	1 Months Ended	3 Months Ended				9 Months Ended	12 Months Ended
	Feb. 28, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Jun. 30, 2017 USD ($) employee	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Sep. 28, 2016 employee
Restructuring Cost and Reserve [Line Items]
Number of employees | employee									36
Restructuring expense		$ 4,442,000	$ 0	$ 0	$ 0		$ 3,040,000	$ 0
Asset impairment costs							1,402,000
Accrued restructuring		2,662,000					2,662,000	0
Accrued restructuring, current		1,609,000					1,609,000	$ 0
Accrued restructuring, long-term		1,100,000					1,100,000
Employee severance and benefit costs							1,500,000
Accrued redemption payments							100,000
Contract termination costs							1,486,000
Lab Equipment
Restructuring Cost and Reserve [Line Items]
Asset impairment costs							555,000
Salvage value		$ 320,000					320,000
Lab Equipment | Subsequent Event
Restructuring Cost and Reserve [Line Items]
Sale of equipment	$ 325,000
Construction in Progress
Restructuring Cost and Reserve [Line Items]
Asset impairment costs							591,000
Furniture, Computers, Equipment and Leasehold Improvements
Restructuring Cost and Reserve [Line Items]
Asset impairment costs							$ 256,000
Scenario, Forecast
Restructuring Cost and Reserve [Line Items]
Number of employees | employee						12
Restructuring expense						$ 4,700,000