Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Cash flows from operating activities:
Net income	$ 75.3	$ 363.1
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	122.1	125.4
Amortization of debt issuance cost and debt discount	1.7	1.8
Change in fair value of contingent consideration	(3.6)
Provision for accounts receivable credit losses	0.7	0.8
(Benefit) provision for deferred income taxes	(146.8)	17.5
Stock-based compensation expense	23.1	22.7
Loss on disposal of property and equipment	0.3
Impairment charge of investment	10.6	5.6
Impairment charge of goodwill	460.9
Equity (earnings) loss in investments	(4.7)	0.4
Gain on investment	(7.5)
Changes in assets and liabilities:
Accounts receivable	(66.9)	14.5
Restricted cash and cash equivalents and customer bank deposits (included in margin deposits and clearing funds)	262.8	853.5
Restricted cash and cash equivalents (included in other current assets)		4.4
Income taxes receivable	3.0	4.8
Digital assets - safeguarded assets	(24.0)
Other current assets	(3.6)	(14.2)
Other assets	(17.4)	(24.6)
Accounts payable and accrued liabilities	28.0	8.9
Digital assets - safeguarded liabilities	24.0
Section 31 fees payable	(2.8)	(143.2)
Deferred revenue	(0.1)	3.7
Income taxes payable	(6.7)	1.4
Unrecognized tax benefits	77.8	32.2
Other liabilities	(11.5)	6.7
Net cash provided by operating activities	794.7	1,285.4
Cash flows from investing activities:
Acquisitions, net of cash acquired	(707.4)	(167.3)
Proceeds from acquisition-related escrow		0.5
Purchases of available-for-sale financial investments	(41.1)	(92.6)
Proceeds from maturities of available-for-sale financial investments	49.8	160.2
Proceeds from investments	1.1
Contributions to investments	(14.6)
Purchases of property and equipment and leasehold improvements	(32.4)	(37.3)
Net cash used in investing activities	(744.6)	(136.5)
Cash flows from financing activities:
Proceeds from long-term debt	663.6	110.0
Principal payments of long-term debt	(100.0)	(20.0)
Debt issuance costs	(4.9)
Cash dividends on common stock	(156.0)	(141.8)
Repurchases of common stock from employee stock plans	(8.8)	(6.0)
Payments of contingent consideration related to acquisitions	(33.2)	(7.1)
Shares issued under employee stock purchase plan	(0.4)	(0.3)
Purchase of common stock	(85.6)	(81.3)
Net cash provided by (used in) financing activities	274.7	(146.5)
Effect of foreign currency exchange rates on cash, cash equivalents, and restricted cash and cash equivalents	(30.5)	2.5
Increase in cash, cash equivalents, and restricted cash and cash equivalents	294.3	1,004.9
Cash, cash equivalents, and restricted cash and cash equivalents: Beginning of period	1,092.2	1,057.5
Cash, cash equivalents, and restricted cash and cash equivalents: End of period	1,386.5	2,062.4
Supplemental disclosure of cash transactions:
Cash paid for income taxes, net of refunds	194.0	144.4
Cash paid for interest	52.4	24.6
Supplemental disclosure of noncash investing activities:
Accounts receivable acquired	4.4	3.5
Financial investments acquired	1.5
Other current assets acquired	1.6	1.1
Goodwill acquired	607.8	134.0
Intangible assets acquired	164.1	73.8
Property and equipment, net acquired	1.6	3.2
Data processing software and other assets acquired	2.0
Operating lease right of use asset acquired	1.2
Other assets, net acquired		0.5
Accounts payable and accrued liabilities acquired	(6.1)	(1.8)
Income taxes payable acquired		(0.1)
Deferred revenue acquired	(0.6)
Operating lease liability - non-current acquired	(1.2)
Contingent consideration related to acquisitions	(7.7)	$ (49.6)
Deferred income taxes acquired	(40.3)
Other non-current liabilities acquired	(0.4)
Paycheck Protection Program loan forgiveness	$ 1.3