Fair Value Disclosures - Investments Measured at Fair Value Based on Net Asset Value Per Share (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
May 31, 2020	Nov. 30, 2019
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	$ 905,484	$ 570,310
Unfunded Commitments	11,823	12,108
Equity Long/Short Hedge Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	302,790	291,593
Unfunded Commitments	$ 0	$ 0
Percentage of redeemable investments	6.00%	6.00%
Notice period redemption of investment prior written notice period	60 days	60 days
Equity Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	$ 21,182	$ 27,952
Unfunded Commitments	$ 11,823	12,108
Expected period for the liquidation of the underlying assets, minimum	1 year
Expected period for the liquidation of the underlying assets, maximum	9 years
Commodity Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	$ 13,593	16,025
Unfunded Commitments	$ 0	0
Notice period redemption of investment prior written notice period	60 days
Multi-asset Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	$ 543,191	234,583
Unfunded Commitments	$ 0	$ 0
Multi-asset Funds \| 60 Days Prior Written Notice
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Percentage of redeemable investments	58.00%	5.00%
Notice period redemption of investment prior written notice period	60 days
Multi-asset Funds \| 30 Days Prior Written Notice
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Notice period redemption of investment prior written notice period	30 days
Other Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	$ 24,728	$ 157
Unfunded Commitments	$ 0	$ 0
Percentage of redeemable investments	99.00%	0.00%
Notice period redemption of investment prior written notice period	12 months

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Expected Period For Liquidation Of Underlying Assets Minimum

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

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Fair value of investment other than investment in equity security, investment in debt security and equity method investment. Includes, but is not limited to, investment in certain entities that calculate net asset value per share. Example includes, but is not limited to, investment in hedge fund, venture capital fund, private equity fund, and real estate partnership or fund.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 6A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=SL6742756-110258

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 35
-Paragraph 54B
-URI http://asc.fasb.org/extlink&oid=117332851&loc=SL7495116-110257

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The amount of unfunded commitments for which the entity is obligated, to those certain investments for which net asset value per share is calculated (including by unit, membership interest, or other equity (ownership interest) unit measure) (alternative investments).

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 6A
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