Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Finite Lived Intangible Assets [Line Items]
Accumulated goodwill impairment losses	$ 0
Amortization of intangible assets	1,162,000	$ 781,000	$ 831,000
FeedbackNow [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets acquired	4,800,000
Amortization of intangible assets	400,000
SocialGlimpz Inc. [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets acquired	$ 600,000