Commitments, Contingencies And Guarantees (Narrative) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013 signs lawsuits
Stockholder Litigation [Abstract]
Derivative lawsuits	2
Lawsuit filing date	March 2012
Breach date	December 2009
Special litigation committee formation date	April 4, 2012
Binding memorandum of understanding date	March 28, 2013
Stipulation of Settlement execution date	July 8, 2013
Settlement hearing scheduling date	July 9, 2013
Hearing date	September 9, 2013
Stipulation of Settlement 8-K filing date	July 9, 2013
Los Angeles Litigation [Abstract]
Lawsuit date	2008
Settlement agreement date	November 2006
Ruling date	January 2010
Conversion from static to digital	83
Upholding date	December 10, 2012
Review request date	January 22, 2013
Review denial date	February 27, 2013
Invalidation date	April 12, 2013
Digital modernization permits issued to Company	82
Digital modernization permits issued to competitor	13
Turn off date	April 15, 2013
Further proceedings conducted date	April 16, 2013
Structures requested to be demolished	82
Motion hearing date	September 16, 2013
Guarantees [Abstract]
Surety bonds outstanding	$ 53.9
Commercial standby letters of credit outstanding	125.1
Cash securing letters of credit	57.2
Letters of credit as collateral	5.0
Outstanding bank guarantees related to international subsidiaries	50.9
Cash collateral of bank guarantees	$ 12.0