Consolidated Investment Products (Beginning And Ending Fair Value Measurements For Level 3 Assets And Liabilities) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance (Asset)	$ 24.1	$ 0	$ 16.2	$ 0
Purchases (Asset)	3.0	0	7.0	0
Sales (Asset)	(0.2)	0	0.5	0
Gains and losses included in the Consolidated Statement of Income (Asset)	(0.3)	0	(4.5)	0
Ending balance (Asset)	27.2	13.2	27.2	13.2
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Net unrealized gains/losses attributable to investments	26.4	6.0	55.8	(8.0)
Level 3 Assets [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance (Asset)	691.1	508.3	500.9	602.9
Purchases (Asset)	58.9	8.3	198.4	21.6
Sales (Asset)	(53.7)	(24.5)	(104.1)	(115.7)
Issuances (Asset)	0	0	1.8	3.8
Settlements (Asset)	0	0	0	0
Deconsolidation of CIP	0	0	0	(18.4)
Gains and losses included in the Consolidated Statement of Income (Asset)	6.3	14.7	105.6	19.2
Transfers to Level 2		0		(6.1)
Foreign exchange (Asset)		0		(0.5)
Ending balance (Asset)	702.6	506.8	702.6	506.8
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Deconsolidation of CIP	0	0	0	(18.4)
Level 3 Liabilities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Deconsolidation of CIP	0	0	339.0	0
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance (Liability)	(4,301.5)	(4,044.3)	(4,181.7)	(3,899.4)
Purchases (Liability)	0	0	0	0
Sales (Liability)	0	0	0	0
Issuances (Liability)	(624.8)	(408.1)	(1,338.9)	(813.1)
Settlements (Liability)	212.5	410.9	510.2	768.2
Deconsolidation of CIP	0	0	339.0	0
Gains and losses included in the Consolidated Statements of Income (Liability)	3.5	43.7	(38.9)	(54.8)
Transfers to Level 2		0		0
Foreign exchange (Liability)		(5.3)		(4.0)
Ending balance (Liability)	$ (4,710.3)	$ (4,003.1)	$ (4,710.3)	$ (4,003.1)