Commitments and Contingencies (Details) ft² in Thousands, € in Millions					1 Months Ended		3 Months Ended		9 Months Ended		12 Months Ended
	Apr. 02, 2015	Mar. 23, 2015 EUR (€)	Mar. 23, 2015 USD ($)	Sep. 16, 2013 USD ($)	Sep. 30, 2016 USD ($) ft²	Aug. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2010 defendant item
Loss Contingencies [Line Items]
Number of defendants | defendant												4
Probable or reasonably possible loss					$ 0		$ 0		$ 0
Operating leases, future minimum payments due					27,800,000		27,800,000		27,800,000
Operating leases, future minimum, sublease receipts					$ 1,100,000		1,100,000		1,100,000
Rent expense							600,000	$ 500,000	$ 1,700,000	$ 1,700,000
Area of office lease | ft²					64
Office lease term, months									129 months
Office lease, monthly rental rate									$ 144,000
Office and laboratory lease period free of charge									9 months
Amount of contribution											$ 15,400,000
Amount of companies cumulative investment and spending									$ 18,800,000
Penalty amount									$ 1,500,000
Number of days in which penalty needs to be paid									30 days
Cure period									90 days
Expected Costs to Transfer Product Line						$ 100,000
Penalty payment derivative					$ 400,000		400,000		$ 400,000		$ 400,000
Proceeds from public stock offering, net of offering costs									39,800,000
Revenue							103,312,000	$ 83,560,000	301,586,000	$ 250,316,000
Securities lock up agreement period	60 days							180 days
Restoration Costs Upon Lease Termination					2,800,000		2,800,000		2,800,000
Finisar Corp Member
Loss Contingencies [Line Items]
Loss Contingency, Pending Claims, Number | item												2
Maximum [Member]
Loss Contingencies [Line Items]
Office lease, monthly rental rate									194,000
Pending Litigation Member
Loss Contingencies [Line Items]
Partial settlement of claims				$ 492,000
Accrual for estimated net litigation expense		€ 1	$ 1,100,000
Embedded Derivative Financial Instruments [Member] | Maximum [Member]
Loss Contingencies [Line Items]
Other non-current liability					5,000,000		5,000,000		5,000,000
RUSSIAN FEDERATION
Loss Contingencies [Line Items]
Exit fees									3,500,000
Exit fees for future									2,000,000
Private Placement [Member] | Embedded Derivative Financial Instruments [Member]
Loss Contingencies [Line Items]
Penalty payment derivative					100,000		100,000		100,000
Additional paid-in capital					4,900,000		4,900,000		4,900,000
Private Placement [Member] | Performance Guarantee [Member]
Loss Contingencies [Line Items]
Other non-current liability					$ 30,000,000		$ 30,000,000		$ 30,000,000