Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Acquired Finite Lived Intangible Assets [Line Items]
Amortization expense	$ 67,000	$ 0	$ 193,000	$ 0
Definite-lived intangible assets, amortization expense, remainder of 2018	266,000		266,000
Definite-lived intangible assets, amortization expense, 2019	285,000		285,000
Definite-lived intangible assets, amortization expense, 2020	265,000		265,000
Definite-lived intangible assets, amortization expense, 2021	248,000		248,000
Definite-lived intangible assets, amortization expense, 2022	$ 145,000		$ 145,000
OneClick Acquisitions [Member] | Tradenames [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Amortization period			60 months
OneClick Acquisitions [Member] | Covenants Not To Compete [Member] | Minimum [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Amortization period			44 months
OneClick Acquisitions [Member] | Covenants Not To Compete [Member] | Maximum [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Amortization period			48 months