Acquisitions - Additional Information (Detail) (USD $)	3 Months Ended	6 Months Ended			0 Months Ended	3 Months Ended		6 Months Ended		0 Months Ended
	Jun. 30, 2014	Jun. 30, 2014		Dec. 31, 2013	Oct. 09, 2013 Antenna	Jun. 30, 2014 Antenna	Mar. 31, 2014 Antenna	Jun. 30, 2014 Antenna	Oct. 09, 2013 Antenna	Apr. 28, 2014 MeshLabs
Business Acquisition [Line Items]
Purchase price of acquired company					$ 27,100,000		$ 800,000	$ 27,141,000		$ 800,000
Cash purchase price deposited in escrow									4,200,000
Acquisition-related costs	157,000	363,000				100,000		300,000
Revenue of the acquiree for the period						4,100,000		8,700,000
Net earnings (loss) of the acquiree for the period						2,800,000		5,200,000
Purchase price adjustment against goodwill		2,866,000	[1]			3,500,000	600,000
Goodwill	40,463,000	40,463,000		40,329,000		19,878,000		19,878,000
Deferred tax assets						36,900,000		36,900,000
Defered tax assets, valuation allowance						24,200,000		24,200,000
Deferred tax liability						6,800,000		6,800,000
Deferred tax assets, net						5,862,000		5,862,000
Acquired identifiable intangibles	$ 10,355,000	$ 10,355,000				$ 10,355,000		$ 10,355,000

[1] The purchase price adjustments identified during the first six months of 2014 have been retroactively applied as of December 31, 2013.