Accrued Expenses and Other Current Liabilities (Schedule of Accrued Expenses and Other Current Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Accounts Payable and Accrued Liabilities, Current [Abstract]
Payroll and other related benefits	$ 39,920	$ 51,591
Bandwidth and co-location	29,291	21,787
Property, use and other taxes	9,923	15,849
Professional service fees	4,162	2,678
Contingent consideration	0	990
Other	2,075	1,766
Total	$ 85,371	$ 94,661