Accrued Liabilities (Details) - USD ($)	Jan. 31, 2016	Jan. 31, 2015
Accrued Liabilities
Accrued salaries, vacation and related benefits	$ 28,700,000	$ 14,900,000
Accrued commissions	6,200,000	5,300,000
Income taxes payable	11,400,000	23,300,000
Accrued interest	11,700,000	9,000,000
Other accrued taxes	2,800,000	6,900,000
Accrued legal fees	6,500,000
Other accrued liabilities	48,000,000	38,700,000
Total accrued liabilities	$ 115,300,000	$ 98,100,000