Stockholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended
Apr. 30, 2019	Apr. 30, 2018
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	$ 1,189,009	$ 1,120,689
Equity awards exercised/vested, net	40	56
Share-based compensation expense	4,227	3,774
Taxes paid for net share settlements	(5,686)	(1,085)
Other comprehensive loss, net	(3,227)	3,436
Other comprehensive gain, net		3,333
Net income	12,043	9,885
Balance at end of period	1,186,826	1,082,924
ASU 2016-02
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of adoption of ASC	(9,580)
ASU 2014-09
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of adoption of ASC		(53,728)
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	264	245
Equity awards exercised/vested, net		17
Balance at end of period	264	262
Additional Paid-in Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	464,112	451,844
Equity awards exercised/vested, net	(5,818)	(98)
Share-based compensation expense	4,227	3,774
Taxes paid for net share settlements	(5,686)	(1,085)
Other comprehensive gain, net		(37)
Balance at end of period	456,835	454,398
Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	(15,194)	(5,522)
Other comprehensive loss, net	(3,227)
Other comprehensive gain, net		3,436
Balance at end of period	(18,421)	(2,086)
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	758,881	674,542
Other comprehensive gain, net		(66)
Net income	12,043	9,885
Balance at end of period	761,344	630,633
Retained Earnings \| ASU 2016-02
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of adoption of ASC	(9,580)
Retained Earnings \| ASU 2014-09
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of adoption of ASC		(53,728)
Common Stock Held in Treasury
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	(19,054)	(420)
Equity awards exercised/vested, net	5,858	137
Balance at end of period	$ (13,196)	$ (283)

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The amount of adjustment to stockholders' equity associated with an employee's income tax withholding obligation as part of a net-share settlement of a share-based award.

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Amount of increase to additional paid-in capital (APIC) from recognition of equity-based compensation.

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Amount of the related income tax effect of a cumulative effect on retained earnings.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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Gross value of stock (or other type of equity) issued during the period as a result of any equity-based compensation plan other than an employee stock ownership plan (ESOP). Stock issued could result from the issuance of restricted stock, the exercise of stock options, stock issued under employee stock purchase plans, and/or other employee benefit plans.

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Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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