Commitments and Contingencies - Summary of Accrual for Environmental Loss Contingencies (Details) $ in Thousands	3 Months Ended
Apr. 30, 2017 USD ($)
Site Contingency [Line Items]
Beginning balance	$ 5,001
Change in estimate	0
Utililzation	(50)
Ending balance	4,951
Accrued Liability [Member]
Site Contingency [Line Items]
Beginning balance	620
Change in estimate	880
Utililzation	(50)
Ending balance	1,450
Other Long-term Liability [Member]
Site Contingency [Line Items]
Beginning balance	4,381
Change in estimate	(880)
Utililzation	0
Ending balance	$ 3,501

Total costs accrued as of the balance sheet date for environmental loss contingencies.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14326-108349

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 30
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13207-110859

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 25
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6395460&loc=d3e13647-108346

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Amount of expense (reversal of expense) which increases (decreases) the accrual for environmental loss contingencies from revisions in estimates to existing obligations. Excludes changes related to business acquisitions, divestitures, or currency movement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 5.Y.Q2)
-URI http://asc.fasb.org/extlink&oid=27011672&loc=d3e149879-122751

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Amount of cash outflow to settle environmental loss contingencies.

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