Discontinued Operations - Assets and Liabilities of Discontinued Operations (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2014
Disposal Group, Including Discontinued Operation, Assets, Current [Abstract]
Cash and cash equivalents	$ 187	$ 3,856	$ 849	$ 2,982
Total assets of discontinued operations	33,609	29,129
Disposal Group, Including Discontinued Operation, Liabilities, Current [Abstract]
Total liabilities of discontinued operations	31,691	24,391
GovDelivery | Discontinued operations, held-for-sale
Disposal Group, Including Discontinued Operation, Assets, Current [Abstract]
Cash and cash equivalents	187	3,856
Accounts receivables, net of allowance	12,963	3,735
Fixed assets, net of accumulated depreciation and amortization	4,363	4,502
Goodwill	5,575	5,575
Intangible assets, net	7,504	8,952
Other assets included in the disposal group	3,017	2,509
Total assets of discontinued operations	33,609	29,129
Disposal Group, Including Discontinued Operation, Liabilities, Current [Abstract]
Accounts payable	1,111	3,309
Accrued expenses	1,049	2,764
Accrued compensation and benefits	3,076	2,386
Deferred revenue	21,812	14,180
Other liabilities included in the disposal group	4,643	1,752
Total liabilities of discontinued operations	$ 31,691	$ 24,391