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Cash and Cash Equivalents - Additional Information (Detail) (USD $) In Millions, unless otherwise specified | 12 Months Ended
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Jan. 31, 2014
Cash and Cash Equivalents [Line Items] |
Original maturity date | Three months or less
Minimum percentage of cash and cash equivalents invested in U.S. Treasury obligations and repurchase agreements | 80.00%
Joint Venture [Member] |
Cash and Cash Equivalents [Line Items] |
Cash held with consolidated joint venture | $ 117.7

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- Definition No authoritative reference available. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cash -URI http://asc.fasb.org/extlink&oid=6506951 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.1) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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