Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating activities:
Net income	$ 658	$ 492
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	157	158
Stock-based compensation	41	29
Deferred taxes	(3)	(28)
Other	(11)	(21)
Changes in assets and liabilities:
Customer accounts receivable	(600)	(227)
Other current and non-current assets	(35)	15
Section 31 fees payable	27	(35)
Deferred revenue	372	347
Other current and non-current liabilities	(86)	(76)
Total adjustments	(138)	162
Net cash provided by operating activities	520	654
Investing activities:
Capital expenditures	(15)	(26)
Capitalized software development costs	(44)	(39)
Cash paid for acquisitions, net of cash acquired	(249)	(19)
Return of capital from equity method investment	0	44
Proceeds from investments, net	6	0
Net cash used in investing activities	(302)	(40)
Financing activities:
Proceeds from commercial paper, net of repayments	503	54
Repurchases of common stock	(699)	(440)
Dividends to stockholders	(166)	(157)
Payments relating to treasury shares received for restricted stock tax payments and stock option exercises	(69)	(57)
Other	20	4
Net cash used in financing activities	(411)	(596)
Effect of exchange rate changes on cash, cash equivalents and restricted cash and cash equivalents	(9)	1
Net increase (decrease) in cash, cash equivalents, and restricted cash and cash equivalents	(202)	19
Cash, cash equivalents, and restricted cash and cash equivalents, beginning of period	2,188	1,872
Cash, cash equivalents, and restricted cash and cash equivalents, end of period	1,986	1,891
Supplemental cash flow disclosure:
Cash paid for income taxes	127	78
Cash paid for interest	$ 69	$ 79