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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 5)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenues | Customer concentration | AT&T
Credit concentrations and significant customers
Percentage of concentration risk	9.00%	8.00%	10.00%
Revenues | Customer concentration | Verizon
Credit concentrations and significant customers
Percentage of concentration risk	15.00%	15.00%	15.00%
Accounts receivable | Credit concentration | AT&T
Credit concentrations and significant customers
Percentage of concentration risk	18.00%	16.00%
Accounts receivable | Credit concentration | Verizon
Credit concentrations and significant customers
Percentage of concentration risk	13.00%	12.00%

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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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-Publisher FASB

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