Related Party Transactions - Additional Information (Detail)					3 Months Ended	12 Months Ended
	Aug. 11, 2017 USD ($)	Feb. 01, 2017	Oct. 31, 2016 USD ($) Director Consultant shares	May 04, 2016 USD ($) Director shares	Mar. 31, 2015	Dec. 31, 2017 USD ($) ft²	Dec. 31, 2016 USD ($)	Nov. 30, 2011 ft²
Related Party Transaction [Line Items]
Proceeds from issuance of common stock	$ 2,200,000
Number of consultants | Consultant			1
Lease expiration date						Jul. 31, 2020
Rental income						$ 51,216	$ 153,648
San Diego California Facility [Member]
Related Party Transaction [Line Items]
Leased facility, expansion of original premises | ft²								9,849
Lease expiration date		Mar. 31, 2017				Oct. 31, 2018
Rental income						$ 51,000	154,000
Director [Member]
Related Party Transaction [Line Items]
Number of members of board of directors | Director			3	3
Initial public offering, number of shares issued | shares			534,088	58,335
Issuance of warrants to purchase shares of common stock | shares			534,088	40,832
Proceeds from issuance of common stock			$ 587,000	$ 175,000
Director [Member] | Chief Executive Officer [Member]
Related Party Transaction [Line Items]
Number of members of board of directors | Director			7
Claire K.T. Reiss [Member]
Related Party Transaction [Line Items]
Initial public offering, number of shares issued | shares			227,272	204,758
Issuance of warrants to purchase shares of common stock | shares			227,272	143,330
Proceeds from issuance of common stock			$ 250,000	$ 614,273
Beneficial owner percentage of company's common stock			10.00%	10.00%
Consultants [Member]
Related Party Transaction [Line Items]
Initial public offering, number of shares issued | shares			79,090
Issuance of warrants to purchase shares of common stock | shares			79,090
Proceeds from issuance of common stock			$ 87,000
Aegea Biotechnologies, Inc [Member]
Related Party Transaction [Line Items]
Reimbursement for shared patent costs						$ 15,000	$ 19,000
Nonexecutive [Member] | San Diego California Facility [Member]
Related Party Transaction [Line Items]
Leased facility, expansion of original premises | ft²						9,849
Lease agreement date of commencement						Mar. 30, 2015
Leased facility, rent expense per month						$ 12,804
Lease facility, refundable security deposit amount						12,804
Lease expiration date					Jul. 31, 2015
Lease agreement, amount of security deposit applied against additional rents owed						16,000
Lease agreement, amount of additional rents waived						$ 3,200