Accrued Liabilities (Details) - USD ($) $ in Millions	Apr. 30, 2017	Jan. 31, 2017
Accrued Liabilities
Accrued salaries, vacation and related benefits	$ 28.5	$ 31.6
Accrued commissions	6.2	8.7
Income taxes payable	11.6	10.3
Accrued interest	29.4	11.7
Other accrued liabilities	30.4	28.8
Total accrued liabilities	$ 106.1	$ 91.1