Segments of Operations (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015 segment	Mar. 31, 2014
Segment Reporting Information [Line Items]
Number of segments	4us-gaap_NumberOfReportableSegments
Maximum [Member] \| Other [Member]
Segment Reporting Information [Line Items]
Earnings (losses) of managed investment entities attributable to noncontrolling interests (are less than in 2014)		$ 1

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

No definition available.

Name:	us-gaap_NumberOfReportableSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration