Consolidated Investment Products (VIE Balance Sheets Consolidated In Period) (Details) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2014
Variable Interest Entity [Line Items]
Cash and cash equivalents of CIP	$ (167.8)	$ (363.3)
Accounts receivable and other assets of CIP	139.6	173.5
Investments of CIP	3,639.4	6,016.1
Total assets	22,658.2	25,073.2
Debt of CIP	3,061.2	5,437.0
Other liabilities of CIP	181.5	273.7
Total liabilities	14,288.4	16,210.2
Total equity	7,962.5	8,695.7	$ 8,872.8	$ 9,119.8
Total liabilities and equity	22,658.2	$ 25,073.2
CLOs - VIEs [Member]
Variable Interest Entity [Line Items]
Cash and cash equivalents of CIP	(14.4)		(209.2)
Accounts receivable and other assets of CIP	0.0		1.5
Investments of CIP	10.9		567.0
Total assets	25.3		777.7
Debt of CIP	0.0		601.4
Other liabilities of CIP	0.7		176.3
Total liabilities	0.7		777.7
Total equity	24.6		0.0
Total liabilities and equity	25.3		777.7
VOEs [Member]
Variable Interest Entity [Line Items]
Cash and cash equivalents of CIP			(10.0)
Accounts receivable and other assets of CIP			0.0
Investments of CIP			0.0
Total assets			10.0
Debt of CIP			0.0
Other liabilities of CIP			0.0
Total liabilities			0.0
Total equity			10.0
Total liabilities and equity			$ 10.0
Variable Interest Entity, Not Primary Beneficiary, Aggregated Disclosure [Member] | CLOs - VIEs [Member]
Variable Interest Entity [Line Items]
Cash and cash equivalents of CIP	(17.7)
Accounts receivable and other assets of CIP	1.1
Investments of CIP	77.4
Total assets	96.2
Debt of CIP	0.0
Other liabilities of CIP	2.3
Total liabilities	2.3
Total equity	93.9
Total liabilities and equity	$ 96.2