Fair Value Disclosures - Investments Measured at Fair Value Based on Net Asset Value Per Share (Footnote) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Feb. 28, 2015	Nov. 30, 2014
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Investments, at fair value	169,964	168,541
Equity Long/Short Hedge Funds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Percentage of redeemable investments	100.00%	99.00%
Fund of Funds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Percentage of investments with no redemption provisions	96.00%	95.00%
Estimated period for the liquidation of the underlying assets, Maximum	2 years
Private equity funds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Estimated period for the liquidation of the underlying assets, Maximum	8 years
Percentage of investments at fair value expected to liquidate	99.00%	99.00%
Estimated period for the liquidation of the underlying assets, Minimum	1 year
Convertible bonds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Redeemable period of investments	5 days
Investments which are not investment companies [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Investments, at fair value	130,700	128,800
Minimum [Member] \| Equity Long/Short Hedge Funds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Notice period redemption of investment prior written notice period	30 days
Maximum [Member] \| Equity Long/Short Hedge Funds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Notice period redemption of investment prior written notice period	90 days

Estimated period for the liquidation of the underlying assets, maximum.

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- Definition

Estimated period for the liquidation of the underlying assets, Minimum.

+ References

No definition available.

+ Details

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- Definition

Investments at fair value that cannot be redeemed at reporting date and are subject to a prior written redemption request.

+ References

No definition available.

+ Details

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- Definition

Expected to liquidate in one to eleven years.

+ References

No definition available.

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- Definition

Percentage of investment with no redemption provisions.

+ References

No definition available.

+ Details

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- Definition

Investments redeemable within 60-90 days

+ References

No definition available.

+ Details

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- Definition

Redeemable period of investments.

+ References

No definition available.

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- Definition

The fair value as of the balance sheet date of firm holdings in private equity, mezzanine, venture capital, merchant banking, real estate and special situations investments. Includes both pledged (to counterparties as collateral for financing transactions) and unpledged holdings.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 940

-SubTopic 320

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=35711157&loc=d3e42546-110969

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