Schedule of Qualifying and Valuation Accounts (Details) (Allowance for Doubtful Accounts, Current [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Allowance for Doubtful Accounts, Current [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation allowance, beginning balance	$ 2,201,875	$ 1,891,334	$ 1,639,198
Acquisitions and dispositions			(28,954)
Charged to costs and expenses	2,080,381	1,959,194	1,766,201
Write-offs	(1,833,824)	(1,648,653)	(1,485,111)
Valuation allowance, ending balance	$ 2,448,432	$ 2,201,875	$ 1,891,334