Fair Value Measurements (Details) - USD ($) $ in Thousands	Apr. 30, 2018	Jan. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Life Insurance, Corporate or Bank Owned, Amount	$ 43,800	$ 44,800
Deferred Compensation Liability, Current and Noncurrent	43,100	44,700
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Foreign currency forward contracts - Assets	11,142	5,025
Foreign currency forward contracts - Liabilities	7,132	11,675
Senior Notes | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt Instrument, Fair Value Disclosure	981,000	$ 1,020,000
Term loan credit agreement
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Other Loans Payable, Long-term, Noncurrent	$ 500,000