Long-Term Debt (Narrative) (Details) (USD $)	0 Months Ended		3 Months Ended		6 Months Ended							6 Months Ended						0 Months Ended	3 Months Ended	6 Months Ended
	Mar. 15, 2012	Mar. 12, 2012	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Mar. 31, 2012	Dec. 31, 2011	Jun. 30, 2012 9.25% Series B Senior Notes Due 2017 [Member]	Jun. 30, 2012 9.25% Series A Senior Notes Due 2017 [Member]	Mar. 31, 2012 7.625% Series B Senior Subordinated Notes	Jun. 30, 2012 7.625% Series A Senior Subordinated Notes	Mar. 31, 2012 7.625% Series A Senior Subordinated Notes	Mar. 31, 2012 Senior Secured Credit Facility [Member]	Mar. 15, 2012 Senior Secured Credit Facility [Member]	Mar. 31, 2012 Revolving Credit Facility [Member]	Mar. 31, 2012 International Subsidiaries Sublimit [Member]	Mar. 15, 2015 Subordinated Debt [Member]	Mar. 31, 2012 Subordinated Debt [Member]	Jun. 30, 2012 Subordinated Debt [Member]	Mar. 31, 2012 Before Repayments [Member] Revolving Credit Facility [Member]	Mar. 31, 2012 Before Repayments [Member] International Subsidiaries Sublimit [Member]
Debt Instrument [Line Items]
Market value			$ 4,900,000,000		$ 4,900,000,000			$ 2,700,000,000
Debt instrument, face amount											1,925,000,000		275,000,000
Stated interest rate									9.25%	9.25%	7.625%		7.625%
Maturity date									2017	2017	2020		2020
Line of Credit Facility, Maximum Borrowing Capacity																10,000,000	750,000				1,900,000,000	145,000,000
Debt Instrument, Payment Terms																				Interest on the Subordinated Notes is payable to the trustee weekly in arrears and to the noteholders on March 15 and September 15 of each year, beginning on September 15, 2012
Debt Instrument Latest Call Date												March 15, 2015
Redemption percentage equal to principal																		100.00%
Maximum Debt Instrument Principal Redemption Amount Not Subject To Make Whole Premium																		40.00%
Debt Instrument Redemption Price As Percentage Of Principal Amount No for any debt reedemed prior to March 15 with no make whole premium.																		107.625%
Purchase Redemption Ratio																				0.25%
Total debt issuance costs																			40,000,000
Purchaser's discount																			33,000,000
Related Party Loan to CCOI							2,167,000,000
Dividends declared per share			$ 0	$ 0	$ 6.0832	$ 0
Dividends Payable Date Of Record		March 12, 2012
Dividends Payable Date To Be Paid	March 15, 2012
Prepayments of Debt														$ 170,500,000	$ 1,925,700,000