Operating Results for Business Segments, with Reconciliations from Segment Profit to Loss Before Income Taxes and Equity in (Earnings) of Equity-Method Investment (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Revenues:
Data center services	$ 39,938	$ 31,542
IP services	27,090	27,862
Total revenues	67,028	59,404
Direct costs of network, sales and services, exclusive of depreciation and amortization:
Data center services	20,970	18,530
IP services	10,184	10,500
Total direct costs of network, sales and services, exclusive of depreciation and amortization	31,154	29,030
Segment profit:
Data center services	18,968	13,012
IP services	16,906	17,362
Total segment profit	35,874	30,374
Restructuring	43	189
Other operating expenses, including direct costs of customer support, depreciation and amortization	34,123	31,073
Income (loss) from operations	1,708	(888)
Non-operating expense	1,626	686
Income (loss) before income taxes and equity in (earnings) of equity-method investment	$ 82	$ (1,574)