Condensed Consolidated Statements Of Income (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Operating revenues:
Investment management fees	$ 780.6	$ 819.1	$ 1,572.0	$ 1,611.4
Service and distribution fees	187.1	211.4	376.1	410.1
Performance fees	15.4	7.6	35.9	11.4
Other	25.9	31.9	58.7	64.4
Total operating revenues	1,009.0	1,070.0	2,042.7	2,097.3
Operating expenses:
Employee compensation	304.6	318.3	623.1	624.2
Third-party distribution, service and advisory	316.6	341.8	633.7	666.3
Marketing	26.6	26.1	53.3	51.8
Property, office and technology	68.5	61.9	135.3	125.9
General and administrative	88.7	77.6	162.0	151.2
Transaction and integration	1.1	11.3	2.6	19.2
Total operating expenses	806.1	837.0	1,610.0	1,638.6
Operating income	202.9	233.0	432.7	458.7
Other income/(expense):
Equity in earnings of unconsolidated affiliates	6.9	10.8	16.6	17.5
Interest and dividend income	2.2	2.4	4.6	4.5
Interest income of consolidated investment products	68.7	79.8	137.7	154.0
Other gains/(losses) of consolidated investment products, net	77.2	(64.7)	(44.7)	(150.2)
Interest expense	(13.4)	(16.0)	(27.0)	(32.2)
Interest expense of consolidated investment products	(46.9)	(46.5)	(92.5)	(86.5)
Other gains and losses, net	(7.7)	6.0	10.9	13.9
Income before income taxes	289.9	204.8	438.3	379.7
Income tax provision	(62.3)	(75.4)	(135.9)	(151.0)
Net income	227.6	129.4	302.4	228.7
Net (income)/loss attributable to noncontrolling interests in consolidated entities, net	(73.7)	53.6	45.4	131.8
Net income attributable to common shareholders	$ 153.9	$ 183.0	$ 347.8	$ 360.5
Earnings per share:
- basic	$ 0.34	$ 0.39	$ 0.77	$ 0.77
- diluted	$ 0.34	$ 0.39	$ 0.76	$ 0.77
Dividends declared per share	$ 0.1725	$ 0.1225	$ 0.2950	$ 0.2325