Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Net cash (used in) provided by operating activities
Net Income	$ 168.8	$ 544.8
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Stock-based compensation	69.5	59.4
Amortization of deferred sales commissions	12.4	18.4
Depreciation and other amortization	25.1	22.4
Amortization of intangible assets	83.2	58.3
Net gains on investments	(45.5)	(25.8)
Income from investments in equity method investees	(33.2)	(24.7)
Net losses (gains) on investments of consolidated investment products	72.3	(88.0)
Net purchase of investments by consolidated investment products	(259.2)	(67.9)
Deferred income taxes	(122.5)	(34.8)
Other	17.8	8.3
Changes in operating assets and liabilities:
Decrease (increase) in receivables and other assets	14.6	(140.6)
Increase in investments, net	(13.6)	(44.6)
Decrease in accrued compensation and benefits	(481.6)	(273.1)
Increase in income taxes payable	158.8	174.5
Increase (decrease) in accounts payable, accrued expenses and other liabilities	59.8	(6.3)
Increase (decrease) in accounts payable and accrued expenses of consolidated investment products	17.0	(13.9)
Net cash (used in) provided by operating activities	(256.3)	166.4
Net cash used in investing activities
Purchase of investments	(234.4)	(321.7)
Liquidation of investments	217.6	388.8
Purchase of investments by consolidated collateralized loan obligations	(822.5)	(839.2)
Liquidation of investments by consolidated collateralized loan obligations	328.7	435.2
Additions of property and equipment, net	(27.4)	(16.7)
Acquisitions, net of cash acquired	(493.7)	(372.3)
Payments of contingent consideration asset	2.9	3.9
Net deconsolidation of investment products	(13.8)	(6.6)
Net cash used in investing activities	(1,042.6)	(728.6)
Net cash provided by financing activities
Dividends paid on common stock	(148.4)	(143.1)
Repurchase of common stock	(14.2)	(21.7)
Proceeds from repurchase agreement	174.8	0.0
Proceeds from debt of consolidated investment products	955.3	1,727.6
Payments on debt of consolidated investment products	(277.9)	(1,228.1)
Payments on contingent consideration liabilities	(2.0)	(4.0)
Noncontrolling interests	271.3	136.6
Net cash provided by financing activities	958.9	467.3
Effect of exchange rate changes on cash and cash equivalents	59.7	(8.0)
Decrease in cash and cash equivalents	(280.3)	(102.9)
Cash and cash equivalents, beginning of period	4,782.5	4,647.2
Cash and Cash Equivalents, End of Period	4,502.2	4,544.3
Supplemental Disclosure of Cash Flow Information
Cash paid for income taxes	13.2	17.6
Cash paid for interest	4.3	8.5
Cash paid for interest by consolidated investment products	$ 50.5	$ 37.4