Fair Value Measurement - Additional Information (Detail) - USD ($) $ in Thousands	Jul. 31, 2016	Jan. 31, 2016
Fair Value, Liabilities Measured on Recurring and Nonrecurring Basis
Notes payable (Note 6)	$ 244,029	$ 240,076
Business Combination, Contingent Consideration, Liability, Current	1,043	1,460
Business Combination, Contingent Consideration, Liability, Noncurrent	1,323	2,289
Current portion of notes payable	0	0
Non-marketable equity securities	3,000
4.00% Debentures due 2031
Fair Value, Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of notes payable	276,978	255,487
Notes payable (Note 6)	238,841	234,888
Notes Payable, Other Payables
Fair Value, Liabilities Measured on Recurring and Nonrecurring Basis
Notes payable (Note 6)	$ 5,188	$ 5,188

Amount of liability recognized arising from contingent consideration in a business combination, expected to be settled within one year or the normal operating cycle, if longer.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 35
-Paragraph 1
-Subparagraph b
-URI http://asc.fasb.org/extlink&oid=6911338&loc=d3e6819-128478

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 25
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-URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6408-128476

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Amount of liability recognized arising from contingent consideration in a business combination, expected to be settled beyond one year or the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 25
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6408-128476

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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.

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No definition available.

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Carrying value as of the balance sheet date of notes payable (with maturities initially due after one year or beyond the operating cycle if longer), excluding current portion.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
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Sum of the carrying values as of the balance sheet date of the portions of all long-term notes and loans payable due within one year or the operating cycle if longer.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Fair value portion of notes payable.

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Aggregate carrying value of owned private equity or other securities for which a quoted market price is not readily determinable, the value of which has been determined by management based upon fair value methods, including pricing of similar securities and valuation techniques and is included in the schedule of financial condition or the balance sheet.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Rule 15c3-1
-Number 240
-Section 15c3-1

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