Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash Flows from Operating Activities:
Net income	$ 157.4	$ 95.2
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	40.5	47.2
Amortization of debt issuance cost and debt discount	0.5	0.6
Change in fair value of contingent consideration		0.8
Realized gain on available-for-sale securities	(0.4)	(0.2)
Provision for credit losses	0.7	0.3
Provision for deferred income taxes	(3.8)	(5.4)
Stock-based compensation expense	8.3	5.4
Loss on disposition of property		0.4
Equity in investments	(0.5)	(0.5)
Changes in assets and liabilities:
Accounts receivable	(164.1)	37.5
Income taxes receivable	45.3	30.1
Other current assets	0.8	(4.3)
Other assets	(6.2)
Accounts payable and accrued liabilities	37.4	(67.0)
Section 31 fees payable	30.1	(32.4)
Deferred revenue	11.4	9.7
Income taxes payable	(0.8)	(1.6)
Unrecognized tax benefits	6.2	6.3
Other liabilities	0.5	(4.1)
Net cash provided by operating activities	163.3	118.0
Cash flows from investing activities:
Acquisitions, net of cash acquired	(61.6)
Purchases of available-for-sale financial investments	(24.5)	(29.5)
Proceeds from maturities of available-for-sale financial investments	47.3	35.3
Return of capital from investments		22.0
Contributions to investments	(1.6)
Purchases of property and equipment	(10.6)	(5.8)
Net cash (used in) provided by investing activities	(51.0)	22.0
Cash flows from financing activities:
Cash dividends paid on common stock	(40.0)	(34.8)
Repurchases of common stock from employee stock plans	(13.9)	(10.0)
Exercise of common stock options		8.1
Payment of contingent consideration from acquisition	(2.3)
Purchase of common stock	(119.5)	(35.0)
Net cash used in financing activities	(175.7)	(71.7)
Effect of foreign currency exchange rates on cash and cash equivalents	(0.7)	2.8
(Decrease) increase in cash and cash equivalents	(64.1)	71.1
Cash and Cash Equivalents: Beginning of Period	229.3	275.1
Cash and Cash Equivalents: End of Period	165.2	346.2
Supplemental disclosure of cash transactions:
Cash paid for income taxes	13.5	2.2
Cash paid for interest	1.6	$ 14.3
Supplemental disclosure of noncash investing activities:
Accounts receivable acquired	0.7
Goodwill acquired	60.4
Intangible assets acquired	20.3
Accounts payable and accrued expenses assumed	(1.4)
Deferred revenue acquired	(1.3)
Contingent consideration related to acquisitions	$ (17.5)