Stockholders' Equity/(Deficit) - Summary of Common Stock Warrants Outstanding (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Class of Warrant or Right [Line Items]
Exercise Price		$ 1.00
Class of Warrant One [Member]
Class of Warrant or Right [Line Items]
Common Stock Warrants	120,000
Exercise Price	$ 3.52
Termination Date	Jan. 10, 2021