Acquisitions - Purchase Price Allocation (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Goodwill	$ 25,007	$ 18,712
Ionia [Member]
Business Acquisition [Line Items]
Cash	67
Current assets	296
Other assets	26
Deferred revenue	(70)
Other liabilities	(864)
Goodwill	6,295
Total purchase price	7,500
Ionia [Member] | Customer Backlog [Member]
Business Acquisition [Line Items]
Business acquisition, Intangible assets	120
Ionia [Member] | Trade Name and Trademark [Member]
Business Acquisition [Line Items]
Business acquisition, Intangible assets	10
Ionia [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Business acquisition, Intangible assets	1,340
Ionia [Member] | Documented Know-how [Member]
Business Acquisition [Line Items]
Business acquisition, Intangible assets	$ 280