Accounts Receivable (Schedule Of Allowance For Doubtful Accounts) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Valuation and Qualifying Accounts Disclosure [Line Items]
Allowance for Doubtful Accounts, End of Period	$ 71,571	$ 71,362
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Allowance for Doubtful Accounts, Beginning of Period	71,362	93,267	107,048
Charged to Other Revenue	61,138	68,965	74,332
Charged (credited) to Switched and Nonswitched Revenue and Other Accounts	(22)	(3,203)	14,396
Write-offs and Recoveries	(60,907)	(87,667)	(102,509)
Allowance for Doubtful Accounts, End of Period	$ 71,571	$ 71,362	$ 93,267