Goodwill and Long-Lived Assets, Net (Major Asset Classes) (Details) - USD ($) $ in Millions	6 Months Ended
	Jul. 31, 2017	Jan. 31, 2017
Goodwill and Intangible Assets Disclosure [Line Items]
Original Cost	$ 428.4	$ 447.7
Accumulated Amortization	119.0	132.9
Net Book Value	309.4	314.8
Indefinite Life, Trade Name
Goodwill and Intangible Assets Disclosure [Line Items]
Original Cost	18.6	16.9
Net Book Value	18.6	16.9
Customer contracts and relationships
Goodwill and Intangible Assets Disclosure [Line Items]
Original Cost	404.3	422.0
Accumulated Amortization	118.1	129.1
Net Book Value	$ 286.2	292.9
Customer contracts and relationships | Minimum
Goodwill and Intangible Assets Disclosure [Line Items]
Useful Life (years)	8 years
Customer contracts and relationships | Maximum
Goodwill and Intangible Assets Disclosure [Line Items]
Useful Life (years)	30 years
Covenants not to compete
Goodwill and Intangible Assets Disclosure [Line Items]
Useful Life (years)	5 years
Original Cost	$ 2.2	5.5
Accumulated Amortization	0.5	3.6
Net Book Value	$ 1.7	1.9
Developed Technologies
Goodwill and Intangible Assets Disclosure [Line Items]
Useful Life (years)	15 years
Original Cost	$ 3.3	3.3
Accumulated Amortization	0.4	0.2
Net Book Value	$ 2.9	$ 3.1