Restructuring Charge (Details)		1 Months Ended	3 Months Ended
	Sep. 26, 2016 USD ($) ft² item shares	Sep. 30, 2016 USD ($) shares	Sep. 30, 2016 USD ($) shares	Jun. 30, 2016 USD ($)	Feb. 29, 2016 USD ($) ft²
Restructuring Cost and Reserve [Line Items]
Restructuring charges			$ 4,130,000
Leasehold improvements impairment			970,000
Construction allowance		$ 6,110,000	6,110,000	$ 6,236,000
Workforce reduction
Restructuring Cost and Reserve [Line Items]
Approximate positions to be eliminated (as a percent)	17.00%
Approximate positions to be eliminated | item	65
Approximate current positions to be eliminated | item	60
Restructuring charges	$ 3,100,000
One-time termination benefit	2,500,000
Benefit plan severance cost	593,000
Additional restructuring charges expected	$ 257,000
Cash payments for restructuring			0
Stock compensation expense (reduction)			(837,000)
Granted (in shares) | shares		847,000
Vesting period		3 years
930 Winter Street, Walham, MA
Restructuring Cost and Reserve [Line Items]
Area of space leased | ft²	10,281				10,281
Estimated period to sub-lease	9 months
Leasehold improvements impairment			970,000
Construction allowance		$ 193,000	$ 193,000		$ 617,000,000
Stock options | Workforce reduction
Restructuring Cost and Reserve [Line Items]
Forfeited (in shares) | shares	762,000		762,000
Stock compensation expense (reduction)			$ (837,000)