EMPLOYEE BENEFIT PLANS - Textuals (Details) - USD ($) $ in Millions	12 Months Ended
Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2017
Defined Contribution Plan Disclosure [Line Items]
Non-discretionary matching contribution	100.00%
Percentage of employee's compensation matched by employer	3.00%
Employer matching percentage of employee contributions	50.00%
Percentage of additional employee's compensation matched by employer	2.00%
DKI
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, matching contributions	$ 3.8	$ 3.6	$ 2.9

Represents defined contribution plan additional maximum annual contributions per employee percent.

No definition available.

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- Definition

Percentage Of Employer Contribution To Match Participant Contribution In Defined Contribution Plan

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No definition available.

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Amount of discretionary contributions made by an employer to a defined contribution plan.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Percentage employer matches of the employee's percentage contribution matched.

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No definition available.

+ Details

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- Definition

Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
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- Details

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