Allocation of Purchase Price for Acquisitions and Enterprise Value of Channel Intelligence (Parenthetical) (Detail)	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Minimum | Technology
Schedule Of Business Acquisitions Purchase Price Allocation [Line Items]
Finite intangible assets, useful life	5 years	5 years
Minimum | Non-compete agreements
Schedule Of Business Acquisitions Purchase Price Allocation [Line Items]
Finite intangible assets, useful life	2 years	2 years
Maximum | Technology
Schedule Of Business Acquisitions Purchase Price Allocation [Line Items]
Finite intangible assets, useful life	10 years	10 years
Maximum | Non-compete agreements
Schedule Of Business Acquisitions Purchase Price Allocation [Line Items]
Finite intangible assets, useful life	5 years	5 years
Superior Access | Technology
Schedule Of Business Acquisitions Purchase Price Allocation [Line Items]
Finite intangible assets, useful life	5 years
Superior Access | Non-compete agreements
Schedule Of Business Acquisitions Purchase Price Allocation [Line Items]
Finite intangible assets, useful life	3 years
Superior Access | Minimum | Customer Lists
Schedule Of Business Acquisitions Purchase Price Allocation [Line Items]
Finite intangible assets, useful life	5 years
Superior Access | Minimum | Trademarks, trade names and domain names
Schedule Of Business Acquisitions Purchase Price Allocation [Line Items]
Finite intangible assets, useful life	5 years
Superior Access | Maximum | Customer Lists
Schedule Of Business Acquisitions Purchase Price Allocation [Line Items]
Finite intangible assets, useful life	11 years
Superior Access | Maximum | Trademarks, trade names and domain names
Schedule Of Business Acquisitions Purchase Price Allocation [Line Items]
Finite intangible assets, useful life	11 years