Income Taxes - Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Millions	Jan. 31, 2020	Jan. 31, 2019
Income Tax Disclosure [Abstract]
Operating lease liabilities	$ 293.7
Pension/postretirement benefits	101.9	$ 82.1
Accrued expenses	21.7	31.3
Share-based compensation	5.7	7.9
Depreciation and amortization	54.7	18.1
Foreign and state net operating losses	6.5	7.0
Sale-leasebacks	0.0	13.1
Inventory	33.3	42.5
Unearned income	7.9	7.2
Other	22.2	28.8
Deferred tax assets, gross	547.6	238.0
Valuation allowance	(10.9)	(8.5)
Deferred tax assets, net of valuation allowance	536.7	229.5
Operating lease right-of-use assets	(301.2)
Foreign tax credit and other tax liabilities	(12.3)	(21.5)
Deferred tax assets, net	$ 223.2	$ 208.0