CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flow from (used in) operating activities:
Net income	$ 1,008.7	$ 739.0	$ 827.2
Adjustments to reconcile Net income to net cash flow from operating activities:
Intangible amortization and impairments	86.4	110.2	115.4
Depreciation and other amortization	20.3	19.5	18.8
Deferred income tax provision	(123.6)	59.3	101.2
Income from equity method investments	(302.2)	(328.8)	(288.9)
Distributions received from equity method investments	429.8	346.4	346.1
Share-based compensation and Affiliate equity expense	90.4	80.4	102.7
Other non-cash items	(26.3)	(16.1)	(38.0)
Changes in assets and liabilities:
Purchases of trading securities by Affiliate sponsored consolidated products	(34.1)	(86.2)	(4.6)
Sales of trading securities by Affiliate sponsored consolidated products	29.9	82.8	4.1
(Increase) decrease in receivables	(53.5)	29.6	54.5
(Increase) decrease in other assets	(7.7)	(6.1)	6.7
Increase (decrease) in payables, accrued liabilities and other liabilities	52.3	20.3	(32.0)
Cash flow from operating activities	1,170.4	1,050.3	1,213.2
Cash flow from (used in) investing activities:
Investments in Affiliates	(30.6)	(1,361.3)	(297.7)
Purchase of fixed assets	(18.5)	(20.2)	(38.2)
Purchase of investment securities	(37.2)	(16.0)	(13.5)
Sale of investment securities	100.1	65.3	24.9
Cash flow from (used in) investing activities	13.8	(1,332.2)	(324.5)
Cash flow from (used in) financing activities:
Borrowings of senior bank debt and senior notes	545.0	1,350.0	1,253.3
Repayments of senior debt, senior notes and convertible securities	(805.0)	(1,125.0)	(1,256.0)
Issuance of common stock	41.9	465.8	57.8
Dividends paid on common stock	(44.9)	0.0	0.0
Repurchase of common stock	(393.2)	(33.4)	(413.7)
Distributions to non-controlling interests	(352.2)	(354.1)	(431.4)
Affiliate equity issuances and repurchases	(165.7)	(104.0)	(120.6)
Excess tax benefit from share-based compensation	0.0	0.0	44.5
Settlement of forward equity sale agreement	5.2	0.0	0.1
Other financing items	(20.8)	1.6	8.3
Cash flow from (used in) financing activities	(1,189.7)	200.9	(857.7)
Effect of foreign exchange rate changes on cash and cash equivalents	14.2	(49.9)	(17.8)
Net increase (decrease) in cash and cash equivalents	8.7	(130.9)	13.2
Cash and cash equivalents at beginning of period	430.8	563.8	550.6
Net cash outflows upon the consolidation and deconsolidation of Affiliate sponsored products	0.0	(2.1)	0.0
Cash and cash equivalents at end of period	439.5	430.8	563.8
Supplemental disclosure of cash flow information:
Interest paid	82.1	85.0	76.4
Income taxes paid	165.0	152.3	89.6
Supplemental disclosure of non-cash financing activities:
Stock issued under incentive plans	59.3	17.2	10.7
Stock received for tax withholdings on share-based payments	20.0	9.8	3.6
Payables recorded for Share repurchases	23.1	0.0	0.0
Payables recorded for Affiliate equity repurchases	47.3	12.1	62.3
Stock received for the exercise of stock options	$ 30.2	$ 11.2	$ 0.0