Intangible Assets (Narrative) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013
Intangible Assets [Abstract]
Gross carrying amount of other intangible assets	$ 57.9
Intangible assets accumulated amortization	36.1
Estimated aggregate amortization expense, remainder of 2013	2.8
Estimated aggregate amortization expense, Year 2014	3.5
Estimated aggregate amortization expense, Year 2015	3.4
Estimated aggregate amortization expense, Year 2016	3.2
Estimated aggregate amortization expense, Year 2017	3.0
Estimated aggregate amortization expense, Year 2018	$ 2.9