Goodwill (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Jun. 30, 2017	Jun. 30, 2017	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill, impairment charge	$ 145.3	$ 145.3
Goodwill, accumulated impairment losses	$ 401.4	$ 401.4	$ 258.6