Commitments And Contingencies (Details) (USD $)	12 Months Ended	3 Months Ended
	Dec. 31, 2012 lawsuit	Jun. 30, 2011 T-Mobile [Member]
Commitments And Contingencies [Line Items]
Longest lease expiration year	2023
Number of putative class action lawsuits	4
Civil penalty for violation of the act maximum first time violation	$ 250
Civil penalty for violation of act, each subsequent transaction	1,000
Loss contingency, estimated reasonably possible loss amount	5,200,000
Charge to earnings		23,400,000
Charge For Vendor Transition		23,400,000
Purchase obligations	313,000,000
Purchase obligations related to 2013	$ 301,700,000