Segment Information - Additional Information (Detail) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016 USD ($) business	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($) business segment	Sep. 30, 2015 USD ($)	Nov. 07, 2016 business
Segment Reporting Information [Line Items]
Number of reporting segments | segment			2
Number businesses owned | business	4		4
Revenue	$ 27,937	$ 24,917	$ 79,977	$ 72,957
Europe and Canada
Segment Reporting Information [Line Items]
Revenue	1,200	800	3,200	2,700
GovDelivery | Discontinued operations, held-for-sale | Non-US [Member]
Segment Reporting Information [Line Items]
Decrease to revenue from discontinued operations	$ 700	$ 700	$ 2,200	$ 2,000
Subsequent Event
Segment Reporting Information [Line Items]
Number businesses owned | business					3