Investment In Cellular Partnership (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Proceeds from sale of interests in the Cellular Partnerships	$ 0	$ 320.0	$ 0
Gain on sale of interests in Cellular Partnerships	0	265.0	0
Net gain on sale of interest in Cellular Partnerships, net of tax		$ 171.8
Cincinnati SMSA Limited Partnership [Member]
Percentage of interest owned by company		33.80%
Cincinnati SMSA Tower Holdings LLC [Member]
Percentage of interest owned by company		45.00%
AT&T [Member] | Cincinnati SMSA Limited Partnership [Member]
Percentage of interest owned by company		66.00%
AT&T [Member] | Cincinnati SMSA Tower Holdings LLC [Member]
Percentage of interest owned by company		53.00%