Accounting Policies (Previously Reported Third-Party Distribution, Service And Advisory And Marketing Expenses) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Third-party distribution, service and advisory expenses	$ 1,311.8	$ 1,282.5	$ 1,053.8	$ 737.0
Marketing expenses	103.0	86.0	78.5	65.3
As Previously Reported [Member]
Third-party distribution, service and advisory expenses			972.7	693.4
Marketing expenses			159.6	108.9
Third-Party Distribution, Service And Advisory Expenses [Member]
Reclassification			81.1	43.6
Marketing Expenses [Member]
Reclassification			$ (81.1)	$ (43.6)