Intangible Assets, net - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense for intangible assets	$ 601,000	$ 546,000	$ 406,000
Finite-Lived Intangible Assets, Remaining Amortization Period	3 years 5 months 5 days