Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)		3 Months Ended
	Apr. 01, 2017	Mar. 31, 2017	Mar. 31, 2016
Summary Of Significant Accounting Policies [Line Items]
Maturity period of highly liquid investments		Three months or less
Grants receivable recognized		$ 82,032	$ 0
Grants remaining to be awarded		2,081,550
Subsequent Event [Member]
Summary Of Significant Accounting Policies [Line Items]
Additional grant received	$ 1,066,648
Level 1 [Member]
Summary Of Significant Accounting Policies [Line Items]
Liabilities		0
Level 2 [Member]
Summary Of Significant Accounting Policies [Line Items]
Liabilities		$ 0