Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash Flows from Operating Activities:
Net income	$ 284.5	$ 286.8
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	133.8	154.9
Amortization of debt issuance cost and debt discount	1.7	1.8
Change in fair value of contingent consideration	2.4	3.0
Realized gain on available-for-sale securities	(1.2)	(1.2)
Provision for uncollectable accounts receivable	0.8
Provision for deferred income taxes	(18.4)	(10.3)
Stock-based compensation expense	17.0	29.4
Loss on disposition of property		1.0
Impairment of assets held for sale	6.1
Loss reelated to deconsolidation of former subsidiary	2.0
Impairment of goodwill	10.5
Equity in investments	(1.7)	(1.2)
Changes in assets and liabilities:
Accounts receivable	49.8	(3.8)
Income taxes receivable	5.4	(42.6)
Other prepaid expenses	(14.8)
Other current assets		(13.1)
Accounts payable and accrued liabilities	(39.4)	(3.8)
Section 31 fees payable	(55.7)	(90.5)
Deferred revenue	(0.3)	(2.0)
Income taxes payable	(3.1)	(3.7)
Income tax liability	20.0	2.9
Other liabilities	(4.3)	0.5
Net Cash Flows provided by Operating Activities	395.1	308.1
Cash Flows from Investing Activities:
Purchases of available-for-sale financial investments	(61.8)	(131.2)
Proceeds from maturities of available-for-sale financial investments	98.0	178.7
Return of capital from investments	22.0
Purchases of investments		(1.8)
Purchases of property and equipment	(26.9)	(27.8)
Net Cash Flows provided by (used in) Investing Activities	31.3	17.9
Cash Flows from Financing Activities:
Proceeds from long-term debt		300.0
Principal payments of long term debt	(350.0)	(325.0)
Proceeds from credit facility		39.0
Payments of credit facility		(39.0)
Dividends paid	(110.0)	(95.6)
Purchase of unrestricted stock from employees	(10.7)	(15.8)
Proceeds from exercise of stock-based compensation	9.1	1.6
Payment of contingent consideration with acquisition of a business		(56.6)
Purchase of common stock under announced program	(87.4)	(140.9)
Net Cash Flows used in Financing Activities	(549.0)	(332.3)
Effect of Foreign Currency Exchange Rate Changes on Cash and Cash equivalents	(2.5)	(0.4)
Increase in Cash and Cash Equivalents	(125.1)	(6.7)
Cash and Cash Equivalents: Beginning of Period	275.1	143.5
Cash and Cash Equivalents: End of Period	150.0	136.8
Supplemental disclosure of cash transactions:
Cash paid for income taxes	98.9	161.7
Interest paid	31.0	$ 33.2
Supplemental disclosure of noncash investing activities:
Note receivable issued in connection with deconsolidation of former subsidiary	3.7
Investment recognized in connection with deconsolidation of former subsidiary	2.9
Net assets of former subsidiary deconsolidated	$ 14.5