Summary of Significant Accounting Policies - Summary of Fair Value of Option Estimated Using Black-Scholes Pricing Model with Valuation Assumptions (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Expected dividend yield	0.00%	0.00%
Expected life at date of issuance	5 years
Minimum [Member]
Risk-free interest rate	2.64%	1.89%
Expected volatility	186.07%	132.87%
Expected life at date of issuance		4 years 6 months 18 days
Maximum [Member]
Risk-free interest rate	2.89%	2.20%
Expected volatility	222.64%	184.92%
Expected life at date of issuance		5 years