Goodwill and Intangibles Net - Additional Information (Detail) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Goodwill And Intangible Assets [Line Items]
Goodwill	$ 107,794,000				$ 21,843,000				$ 107,794,000	$ 21,843,000	$ 19,622,000
Amortization of intangible assets	1,901,000	1,829,000	1,436,000	424,000	399,000	338,000	338,000	337,000	5,590,000	1,412,000	1,357,000
Goodwill impairment charges									304,000
Accumulated amortization	8,802,000				2,769,000				8,802,000	2,769,000
GovDelivery
Goodwill And Intangible Assets [Line Items]
Intangible assets impairment charges									400,000
Goodwill impairment charges									300,000
Accumulated amortization	8,800,000								8,800,000
Procurian
Goodwill And Intangible Assets [Line Items]
Goodwill	30,200,000				17,800,000				30,200,000	17,800,000
Subsidiaries
Goodwill And Intangible Assets [Line Items]
Amortization of intangible assets									$ 5,600,000	$ 1,400,000	$ 1,400,000