Employee Benefit Plans Fair Value of Plan Assets (Details) - USD ($) $ in Millions		Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		$ 578.1	$ 530.1
Fair value of plan assets excluding investments at NAV practical expedient		365.1	297.8
Investments at NAV practical expedient	[1]	213.0	232.3
Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		248.2	213.6
Fair value of plan assets excluding investments at NAV practical expedient		248.2	213.6
Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		116.9	84.2
Fair value of plan assets excluding investments at NAV practical expedient		116.9	84.2
Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		0.0	0.0
Fair value of plan assets excluding investments at NAV practical expedient		0.0	0.0
Equity Securities, Investment Summary [Member] | U.S. equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		74.3	56.2
Equity Securities, Investment Summary [Member] | U.S. equity securities [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		74.3	56.2
Equity Securities, Investment Summary [Member] | U.S. equity securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		0.0	0.0
Equity Securities, Investment Summary [Member] | U.S. equity securities [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		0.0	0.0
Equity Securities, Investment Summary [Member] | Mutual funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		44.7	35.1
Equity Securities, Investment Summary [Member] | Mutual funds [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		44.7	35.1
Equity Securities, Investment Summary [Member] | Mutual funds [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		0.0	0.0
Equity Securities, Investment Summary [Member] | Mutual funds [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		0.0	0.0
Fixed Income Securities [Member] | Government Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		79.0	78.2
Fixed Income Securities [Member] | Government Bonds [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		77.3	77.8
Fixed Income Securities [Member] | Government Bonds [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		1.7	0.4
Fixed Income Securities [Member] | Government Bonds [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		0.0	0.0
Fixed Income Securities [Member] | Corporate Bond Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		115.2	83.8
Fixed Income Securities [Member] | Corporate Bond Securities [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		0.0	0.0
Fixed Income Securities [Member] | Corporate Bond Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		115.2	83.8
Fixed Income Securities [Member] | Corporate Bond Securities [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		0.0	0.0
Other Investments [Member] | Mutual funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		49.6	36.7
Other Investments [Member] | Mutual funds [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		49.6	36.7
Other Investments [Member] | Mutual funds [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		0.0	0.0
Other Investments [Member] | Mutual funds [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		0.0	0.0
Other Investments [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		2.3	7.8
Other Investments [Member] | Cash and Cash Equivalents [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		2.3	7.8
Other Investments [Member] | Cash and Cash Equivalents [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		0.0	0.0
Other Investments [Member] | Cash and Cash Equivalents [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		0.0	0.0
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		$ 578.1	$ 530.1	$ 385.8

[1] In accordance with ASC 820-10, certain investments that are measured at fair value using the net asset value ("NAV") per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the Qualified Plan's fair value of plan assets at the end of each respective year.