v2.4.0.6

Operating Segments and Concentrations of Credit Risk (Major Customers) (Details) | Dec. 31, 2011 | Dec. 31, 2010 | Dec. 31, 2009
--- | --- | --- | ---
Percentage of the consolidated revenues | 74.00% | 73.00% | 74.00%
AT&T [Member] |  |  |
Percentage of the consolidated revenues | 23.00% | 21.00% | 20.00%
Sprint [Member] |  |  |
Percentage of the consolidated revenues | 21.00% | 20.00% | 22.00%
Verizon Wireless [Member] |  |  |
Percentage of the consolidated revenues | 19.00% | 21.00% | 19.00%
T-Mobile [Member] |  |  |
Percentage of the consolidated revenues | 11.00% | 11.00% | 13.00%

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