Cash Dividends Declared to Common Stockholders (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
May 31, 2014	Feb. 28, 2014	Nov. 30, 2013	May 31, 2013	Feb. 28, 2013	Nov. 30, 2012
Earnings Per Share [Abstract]
Dividend Declaration Date	Apr. 17, 2014	Jan. 22, 2014	Oct. 17, 2013	Apr. 15, 2013	Jan. 23, 2013	Oct. 16, 2012
Dividend per Share	$ 0.08	$ 0.08	$ 0.08	$ 0.08	$ 0.08	$ 0.08
Total of Cash Dividends Declared	$ 16,686	$ 16,976	$ 17,221	$ 16,994	$ 16,990	$ 16,962
Date of Record for Dividend Payment	May 15, 2014	Feb. 14, 2014	Nov. 15, 2013	May 15, 2013	Feb. 15, 2013	Nov. 15, 2012
Dividend Cash Payment Date	Jun. 02, 2014	Mar. 03, 2014	Dec. 02, 2013	Jun. 03, 2013	Mar. 01, 2013	Dec. 03, 2012

Date the declared dividend will be paid, in CCYY-MM-DD format.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4304-108586

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- Definition

The per share amount of a dividend declared, but not paid, as of the financial reporting date.

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Carrying value as of the balance sheet date of dividends declared but unpaid on equity securities issued by the entity and outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.15(5))

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 15

-Subparagraph a

-Article 7

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 15

-Subparagraph 5

-Article 9

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.15(5))

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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Date the dividend to be paid was declared, in CCYY-MM-DD format.

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Date the holder must own the stock to be entitled to the dividend, in CCYY-MM-DD format.

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No definition available.

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