Summary of Significant Accounting Policies - Finite-Lived Intangible Assets, Weighted Average Useful Lives and Amortization Methodology (Details)	3 Months Ended
	Mar. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Remaining Weighted Average Useful Lives	8 years
Directory services agreements
Finite-Lived Intangible Assets [Line Items]
Remaining Weighted Average Useful Lives	9 years	[1]
Amortization Method	Income forecast method (1)
Local customer relationships
Finite-Lived Intangible Assets [Line Items]
Remaining Weighted Average Useful Lives	8 years	[1]
Amortization Method	Income forecast method (1)
National customer relationships
Finite-Lived Intangible Assets [Line Items]
Remaining Weighted Average Useful Lives	8 years	[1]
Amortization Method	Income forecast method (1)
Tradenames and trademarks
Finite-Lived Intangible Assets [Line Items]
Remaining Weighted Average Useful Lives	8 years
Amortization Method	Straight-line method
Technology, advertising commitments and other
Finite-Lived Intangible Assets [Line Items]
Remaining Weighted Average Useful Lives	5 years	[1]
Amortization Method	Income forecast method (1)

[1] These intangible assets are being amortized under the income forecast method, which assumes the value derived from these intangible assets is greater in the earlier years and steadily declines over time.