Merger Transaction and Integration Costs (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Business Acquisition [Line Items]
Accumulated merger transaction costs	$ 42,000,000
Merger transaction costs	0	22,000,000	12,000,000
Merger integration costs	41,000,000	54,000,000	0
Total merger related costs	41,000,000	76,000,000	12,000,000
General and Administrative Expense
Business Acquisition [Line Items]
Merger transaction costs	0	22,000,000	12,000,000
Employee Severance
Business Acquisition [Line Items]
Merger integration costs	13,000,000	32,000,000
Dex One
Business Acquisition [Line Items]
Deferred financing costs	$ 8,000,000