Summary of Depreciation and Amortization of Property and Equipment Associated with Direct Costs of Network, Sales and Services and Other Depreciation Expense (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2009
Property, Plant and Equipment [Line Items]
Amortization of acquired technologies	$ 4,134
CDN
Property, Plant and Equipment [Line Items]
Amortization of acquired technologies	$ 4,100