Acquisitions (Details) (USD $)				12 Months Ended			12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Goldman Sachs Administration Services [Member]	Oct. 15, 2012 Goldman Sachs Administration Services [Member]	Dec. 31, 2011 Complementa Investment Controlling Ag And Pulse Trading Inc [Member]	Dec. 31, 2011 Pulse Trading Inc [Member]	Dec. 31, 2011 Complementa Investment Controlling Ag [Member]	Dec. 31, 2011 Bank Of Ireland's Asset Management [Member]	Mar. 31, 2011 Bank Of Ireland's Asset Management [Member]
Business Acquisition [Line Items]
Date of acquisition				Oct. 15, 2012			Nov. 30, 2011	Oct. 31, 2011
Acquisition purchase price					$ 550,000,000
Single manager hedge fund assets under administration					200,000,000,000
Goodwill resulting from acquisition					290,000,000	68,000,000			31,000,000
Intangible assets resulting from acquisition					257,000,000	67,000,000
Other intangible assets	2,539,000,000	2,459,000,000	2,593,000,000						27,000,000
Assets under management through acquisition										$ 23,000,000,000