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								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Revenues:
Data center services									$ 133,453	$ 128,200	$ 130,711
IP services									111,175	115,964	125,548
Total revenues	62,800	62,014	60,410	59,404	59,959	60,315	60,525	63,365	244,628	244,164	256,259
Direct costs of network, sales and services, exclusive of depreciation and amortization:
Data center services									78,907	82,761	94,961
IP services									41,403	44,662	48,055
Total direct costs of network, sales and services, exclusive of depreciation and amortization	29,924	30,787	30,569	29,030	30,508	31,567	31,263	34,085	120,310	127,423	143,016
Segment profit:
Data center services									54,546	45,439	35,750
IP services									69,772	71,302	77,493
Total segment profit									124,318	116,741	113,243
Restructuring and impairments	1,217	123	1,304	189	210		1,183	18	2,833	1,411	54,698
Other operating expenses, including direct costs of customer support, depreciation and amortization									125,408	116,226	127,467
Loss from operations									(3,923)	(896)	(68,922)
Non-operating expense									3,866	2,170	461
Loss before income taxes and equity in (earnings) of equity-method investment									$ (7,789)	$ (3,066)	$ (69,383)