Sterne Agee (Details) $ in Millions	9 Months Ended
Jun. 30, 2019 USD ($)
Business Acquisition [Line Items]
Business Combination, Bargain Purchase, Gain Recognized, Amount	$ 5.4

In a business combination in which the amount of net identifiable assets acquired and liabilities assumed exceeds the aggregate consideration transferred or to be transferred (as defined), this element represents the amount of gain recognized by the entity.

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Name:	us-gaap_BusinessCombinationBargainPurchaseGainRecognizedAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration