Acquisitions - Allocation of Purchase Price - 2013 Acquisitions (Detail) - USD ($) $ in Thousands	Apr. 29, 2013	Apr. 18, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Business Acquisition [Line Items]
Goodwill			$ 29,753	$ 29,753	$ 29,753	$ 23,435
Clara Ehf. [Member]
Business Acquisition [Line Items]
Net assets acquired		$ 6,488
Current assets		81
Goodwill		3,161
Other intangible assets		3,342
Current liabilities		(96)
StreamOnce, Inc. [Member]
Business Acquisition [Line Items]
Cash paid	$ 4,667
Value of common stock issued	852
Contingent consideration	576
Net assets acquired	6,095
Current assets	108
Goodwill	3,157
Other intangible assets	4,248
Current liabilities	(67)
Core technology [Member] | Clara Ehf. [Member]
Business Acquisition [Line Items]
Other intangible assets		$ 2,315
Intangible assets, useful life		5 years
Core technology [Member] | StreamOnce, Inc. [Member]
Business Acquisition [Line Items]
Other intangible assets	$ 3,671
Intangible assets, useful life	5 years
Covenant not to compete [Member] | Clara Ehf. [Member]
Business Acquisition [Line Items]
Other intangible assets		$ 227
Intangible assets, useful life		2 years
Covenant not to compete [Member] | StreamOnce, Inc. [Member]
Business Acquisition [Line Items]
Other intangible assets	$ 459
Intangible assets, useful life	3 years
Customer relationships [Member] | Clara Ehf. [Member]
Business Acquisition [Line Items]
Other intangible assets		$ 570
Intangible assets, useful life		3 years
Trade names [Member] | Clara Ehf. [Member]
Business Acquisition [Line Items]
Other intangible assets		$ 230
Intangible assets, useful life		3 years
Trade names [Member] | StreamOnce, Inc. [Member]
Business Acquisition [Line Items]
Other intangible assets	$ 118
Intangible assets, useful life	3 years