Commitments and Contingencies - Additional Information (Detail)	1 Months Ended	3 Months Ended	6 Months Ended	9 Months Ended	12 Months Ended
	Nov. 30, 2017 USD ($) ft²	Sep. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Jun. 30, 2015 USD ($)	Sep. 30, 2017 USD ($) € / $ shares	Sep. 30, 2017 EUR (€) shares	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Sep. 29, 2015 USD ($)
Commitments And Contingencies [Line Items]
Agreed to pay the customer and settlement of claim									$ 2,500,000
Undisputed royalties earned									$ 500,000
Revenue recognized by company		$ 500,000
Pre tax compensation expense		$ 2,500,000
Additional shares of common stock to stockholders | shares					480,059	480,059
License agreement commencement date					2006-03	2006-03
Annual minimum payments for licenses					$ 236,000	€ 200,000
Exchange rate relating to license payment | € / $					1.1801
Future minimum payments associated with license					$ 2,400,000
Rent expense related to operating leases					100,000		$ 100,000	$ 100,000
CRO [Member]
Commitments And Contingencies [Line Items]
Contractual obligations					26,000,000
Contractual obligation to be paid					23,200,000
CRO [Member] | Minimum [Member]
Commitments And Contingencies [Line Items]
Contractual obligation due in next several years					32,000,000
CRO [Member] | Maximum [Member]
Commitments And Contingencies [Line Items]
Contractual obligation due in next several years					$ 40,000,000
Subsequent Event [Member] | Eden Prairie Minnesota [Member]
Commitments And Contingencies [Line Items]
Square feet of office and R&D facility | ft²	36,000
Contractual obligations	$ 4,000,000
Operating lease agreement term	10 years
Operating lease agreement expected commencement date	2018-05
Patents [Member]
Commitments And Contingencies [Line Items]
Patent expiry date					2027-09	2027-09
January 2009 through September 2014 [Member]
Commitments And Contingencies [Line Items]
Royalties overpaid			$ 5,700,000	$ 5,700,000