Goodwill And Identifiable Intangibles (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2017	Mar. 31, 2018
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill impairment	$ 0.0
Impairment of intangible assets	0.0
Mead Trade Name
Acquired Finite-Lived Intangible Assets [Line Items]
Impairment of intangible assets	$ 0.0
Long-term growth rate	1.50%
Discount rate	10.50%
Maximum percent above carrying value	30.00%
Carrying values of intangible assets		$ 113.3