Collateralized Transactions (Details) - USD ($) $ in Billions	Mar. 31, 2017	Dec. 31, 2016
Collateralized Transactions [Abstract]
Fair value of securities received as collateral that may be sold or repledged	$ 24.7	$ 25.5

Fair value of collateral permitted, by contact or custom, to be sold or re-pledged.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 50
-Paragraph 1A
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=64858031&loc=SL6224234-111729

Name:	us-gaap_FairValueOfSecuritiesReceivedAsCollateralThatCanBeResoldOrRepledged
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant