Summary of Significant Accounting Policies - Additional Information (Details)		3 Months Ended	6 Months Ended
	Nov. 18, 2016 shares	Jun. 30, 2017 USD ($) shares	Jun. 30, 2017 USD ($) shares	Jun. 30, 2016 USD ($) shares	Jun. 16, 2017 shares	Dec. 31, 2016 USD ($) shares	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Disclosure Summary Of Significant Accounting Policies Additional Information Detail [Line Items]
Accumulated deficit		$ (105,657,577)	$ (105,657,577)			$ (96,223,442)
Cash and cash equivalents		1,814,005	1,814,005	$ 11,948,858		11,437,118	$ 22,604,481
Certificates of deposit		466,492	466,492			$ 3,462,617
Write-off of supplies for clinical trials		$ 2,349,404	$ 2,349,404	$ 0
Shares authorized but unissued common stock (in shares) | shares		44,500,061	44,500,061
Tax benefit attributed to the stock-based compensation expense			$ 0
Unrecognized tax benefits		$ 0	0
Liability, interest, or penalties related to unrecognized tax benefits		$ 0	$ 0
Reverse split ratio	0.025
Common stock authorized (in shares) | shares	25,000,000	25,000,000	25,000,000		50,000,000	25,000,000
Shares excluded from the computation of diluted net loss per share (in shares) | shares			1,724,515	928,001
Intellectual Property
Disclosure Summary Of Significant Accounting Policies Additional Information Detail [Line Items]
Fair value of intellectual property								$ 11,000,000
Computer Equipment
Disclosure Summary Of Significant Accounting Policies Additional Information Detail [Line Items]
Estimated useful lives of property and equipment			3 years
Minimum
Disclosure Summary Of Significant Accounting Policies Additional Information Detail [Line Items]
Estimated useful lives of property and equipment			3 years
Maximum
Disclosure Summary Of Significant Accounting Policies Additional Information Detail [Line Items]
Estimated useful lives of property and equipment			5 years
Research and Development Expense
Disclosure Summary Of Significant Accounting Policies Additional Information Detail [Line Items]
Write-off of supplies for clinical trials		$ 2,560,220