Investments - Berkadia - Narrative (Details) - Berkadia Commercial Mortgage, LLC - USD ($) $ in Millions	3 Months Ended	6 Months Ended
May 31, 2019	May 31, 2019	Nov. 30, 2018	Oct. 01, 2018
Schedule of Equity Method Investments [Line Items]
Ownership percentage				50.00%
Percentage of profits received from joint venture				45.00%
Purchase commitment amount	$ 543.4	$ 543.4	$ 723.8
Distribution received from equity method investment	$ 0.8	$ 18.1

Amount of distribution received from equity method investee for return on investment, classified as operating activities. Excludes distribution for return of investment, classified as investing activities.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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