CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Supplemental disclosure of non-cash investing and financing activities:
Capitalized equipment related to the Company's collocation facility	$ 1,631	$ 1,259	$ 259
Net cash paid for income taxes	2,579	3,800	2,000
Pre-acquisition contingency resulting in a decrease in accrued expenses			$ 566