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Accounts Receivable - Additional Information (Detail) (USD $) | 3 Months Ended | 9 Months Ended |  |
--- | --- | --- | --- | ---
Oct. 31, 2014 | Oct. 31, 2014 | Jan. 31, 2014 | Jan. 31, 2010
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |
Length of retention period of amount given to project owners |  | 2 years |  |
Allowance for doubtful accounts | $ 5,500,000 | $ 5,500,000 | $ 5,500,000 |
Accounts receivable from the owner of a partially completed construction project |  |  |  | 5,500,000
Provision for accounts receivable loss | 0 | 0 |  |
Construction Contracts Retainage [Member] |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |
Contract payment amounts retained by project owners | $ 21,000,000 | $ 21,000,000 | $ 22,700,000 |

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- Definition For an unclassified balance sheet, the amount due from customers or clients for goods or services that have been delivered or sold in the normal course of business, reduced to their estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 3 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.9) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.5) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
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