Goodwill and Intangible Assets - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2019 USD ($) Segment	Dec. 31, 2018 USD ($)
Finite Lived Intangible Assets [Line Items]
Change in goodwill	$ 0
Goodwill	$ 3,332,000	$ 3,332,000
Number of reporting segments | Segment	0
Increase (decrease) in cost of intangible assets	$ 200,000
Minimum [Member]
Finite Lived Intangible Assets [Line Items]
Amortization of intangible assets basis over estimated useful lives	1 year
Maximum [Member]
Finite Lived Intangible Assets [Line Items]
Amortization of intangible assets basis over estimated useful lives	6 years