Organization and Summary of Significant Accounting Policies - Restricted Stock and Options Outstanding Used in Per Share Calculations (Detail) - shares shares in Thousands	12 Months Ended
Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Stock options (in shares)	96	77	18
Restricted stock (in shares)	11	32	44
Total dilutive shares	107	109	62

Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 28A
-URI http://asc.fasb.org/extlink&oid=109260490&loc=d3e1500-109256

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration