Fair Value Measurements (Details) - USD ($) $ in Thousands	Jan. 31, 2020	Jan. 31, 2019
Senior Notes
Liabilities, Fair Value Disclosure
Senior Notes	$ 994,300	$ 992,800
Level 1 \| Senior Notes
Liabilities, Fair Value Disclosure
Debt, fair value disclosures	1,040,000	988,000
Other Current Assets [Member] \| Level 2 \| Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure
Net Investment in Foreign Operations, Assets, Fair Value	812	0
Foreign Currency Cash Flow Hedge Asset at Fair Value	124	0
Liabilities, Fair Value Disclosure
Foreign Currency Derivative Instruments Not Designated as Hedging Instruments, Asset at Fair Value	3,675	3,830
Other Noncurrent Assets [Member] \| Level 2 \| Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure
Net Investment in Foreign Operations, Assets, Fair Value	24,933	0
Other Current Liabilities [Member] \| Level 2 \| Fair Value, Measurements, Recurring
Liabilities, Fair Value Disclosure
Foreign Currency Cash Flow Hedge Liability at Fair Value	492	0
Foreign Currency Derivative Instruments Not Designated as Hedging Instruments, Liability at Fair Value	$ 5,916	$ 6,641

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Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

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Fair value as of the balance sheet date of all foreign currency derivative assets designated as cash flow hedging instruments.

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Fair value as of the balance sheet date of all foreign currency derivative liabilities designated as cash flow hedging instruments.

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Fair value of all derivative assets designated as hedges of net investment in foreign operations.

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