Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Net cash provided by operating activities
Net Income	$ 2,094.6	$ 787.1	$ 1,205.5
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation	171.9	122.3	111.5
Amortization of deferred sales commissions	78.2	80.3	85.8
Depreciation and other amortization	78.6	74.5	78.7
Amortization of intangible assets	232.0	54.0	14.7
Impairments of intangible assets and goodwill	0.0	55.4	13.3
Net (gains) losses on investments	(75.5)	15.5	9.7
Losses (income) from investments in equity method investees	(154.3)	98.1	10.4
Net (gains) losses on investments of consolidated investment products	(316.4)	36.8	26.3
Net purchase of investments by consolidated investment products	(781.0)	(682.8)	(1,451.8)
Deferred income taxes	3.7	(7.1)	(1.3)
Other	16.0	(28.7)	17.2
Changes in operating assets and liabilities:
Decrease (increase) in receivables and other assets	(182.5)	134.7	(63.5)
Decrease in investments, net	12.8	537.3	142.4
Increase (decrease) in accrued compensation and benefits	114.8	(10.5)	89.4
Decrease in commissions payable	(8.2)	(33.8)	(43.9)
Decrease in income taxes payable	(12.5)	(123.0)	(210.1)
Increase (decrease) in accounts payable, accrued expenses and other liabilities	(89.1)	(97.4)	126.0
Increase in accounts payable and accrued expenses of consolidated investment products	62.3	70.6	108.2
Net cash provided by operating activities	1,245.4	1,083.3	268.5
Net cash used in investing activities
Purchase of investments	(770.4)	(481.4)	(401.9)
Liquidation of investments	594.0	880.0	343.2
Purchase of investments by consolidated collateralized loan obligations	(3,654.7)	(1,530.3)	(469.6)
Liquidation of investments by consolidated collateralized loan obligations	1,624.2	448.3	88.6
Decrease (increase) in loan receivables, net	42.7	(40.6)	0.0
Additions of property and equipment, net	(79.3)	(103.7)	(233.7)
Acquisitions, net of cash acquired	(9.0)	(3,821.4)	(493.5)
Payments of contingent consideration asset	20.3	0.0	0.0
Net (deconsolidation) consolidation of investment products	(383.7)	587.2	(108.5)
Net cash used in investing activities	(2,615.9)	(4,061.9)	(1,275.4)
Net cash provided by financing activities
Issuance of common stock	22.3	20.6	23.3
Dividends paid on common stock	(559.7)	(533.2)	(518.6)
Repurchase of common stock	(208.2)	(218.2)	(754.5)
Proceeds from issuance of debt	1,193.9	0.0	0.0
Payment of debt issuance costs	(11.8)	0.0	0.0
Payments on debt	(750.0)	0.0	0.0
Proceeds from loan	0.0	0.2	1.7
Payments on loan	0.0	(0.4)	(1.5)
Proceeds from debt of consolidated investment products	2,937.9	1,390.7	681.1
Payments on debt by consolidated investment products	(1,315.7)	(334.2)	(221.4)
Payments on contingent consideration liabilities	0.0	(0.6)	(20.4)
Noncontrolling interests	721.4	409.5	1,150.2
Net cash provided by financing activities	2,030.1	734.4	339.9
Effect of exchange rate changes on cash and cash equivalents	(2.2)	27.4	(37.0)
Increase (decrease) in cash and cash equivalents	657.4	(2,216.8)	(704.0)
Cash and cash equivalents, beginning of year	3,989.8	6,206.6	6,910.6
Cash and Cash Equivalents, End of Year	4,647.2	3,989.8	6,206.6
Supplemental Disclosure of Cash Flow Information
Cash paid for income taxes	498.0	359.4	520.8
Cash paid for interest	116.6	18.9	27.4
Cash paid for interest by consolidated investment products	$ 102.8	$ 65.6	$ 2.3