Goodwill And Intangible Assets (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2015
Goodwill And Intangible Assets
Capitalized intangible assets	$ 14.6	$ 29.2	$ 10.4
Amortization expense	$ 38.2	$ 41.0	$ 49.5