Industry Segments and Geographic Operations (Schedule Of Business Segment Information) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended									12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011		Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenues	$ 508.8	$ 507.6	$ 491.1	$ 497.5	$ 500.5		$ 493.3	$ 474.6	$ 464.8	$ 2,005.0	$ 1,933.2	$ 1,863.3
Depreciation										82.4	76.3	87.6
Amortization										6.3	7.4	7.7
Restructuring charges										11.6	1.2	28.7
Asset Impairments										88.6	0	181.1
Operating income (loss)	31.0	39.1	(60.5)	29.0	30.9	[1]	28.1	26.4	24.7	38.6	110.1	(153.9)
Assets	2,037.9				2,330.8					2,037.9	2,330.8
Long-Lived Assets	937.3				1,379.7					937.3	1,379.7
North America
Revenues										1,836.4	1,790.1	1,716.3
Long-Lived Assets	849.3				957.4					849.3	957.4
Assets Held-for-sale, Long Lived	0				319.7					0	319.7
Rest of World
Revenues										168.6	143.1	147.0
Long-Lived Assets	88.0				102.6					88.0	102.6
At And T [Member] | Customer Concentration Risk [Member] | Sales Revenue, Services, Net [Member]
Concentration risk percent										23.10%	23.40%	23.00%
Accounts Receivable, Net	$ 73.0				$ 82.0					$ 73.0	$ 82.0
Directtv [Member] | Customer Concentration Risk [Member] | Sales Revenue, Services, Net [Member]
Concentration risk percent										12.30%	11.80%	8.60%
Comcast [Member] | Customer Concentration Risk [Member] | Sales Revenue, Services, Net [Member]
Concentration risk percent										12.40%	12.00%	10.50%

[1] (a) Includes asset impairment charge of $88.6.