Identifiable Intangible Assets, Nimbus (Detail) (Nimbus Partners Limited, USD $) In Thousands, unless otherwise specified	1 Months Ended
	Aug. 30, 2011
Acquired Finite-Lived Intangible Assets [Line Items]
Identifiable intangible assets	$ 19,800
Weighted average amortization period	5 years 3 months 18 days
Existing Technology
Acquired Finite-Lived Intangible Assets [Line Items]
Identifiable intangible assets	13,900
Weighted average amortization period	5 years
Subscriber Base
Acquired Finite-Lived Intangible Assets [Line Items]
Identifiable intangible assets	1,200
Weighted average amortization period	5 years
Customer Contracts
Acquired Finite-Lived Intangible Assets [Line Items]
Identifiable intangible assets	700
Weighted average amortization period	5 years
Maintenance Agreements
Acquired Finite-Lived Intangible Assets [Line Items]
Identifiable intangible assets	3,100
Weighted average amortization period	7 years
Trademarks
Acquired Finite-Lived Intangible Assets [Line Items]
Identifiable intangible assets	$ 900
Weighted average amortization period	5 years