Consolidated Statements of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Operating activities:
Net income	$ 970	$ 936
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	315	281
Stock-based compensation	64	61
Deferred taxes	(42)	(7)
Other	(26)	(4)
Changes in assets and liabilities:
Customer accounts receivable	(96)	(148)
Other current and non-current assets	3	(39)
Section 31 fees payable	63	80
Deferred revenue	229	249
Other current and non-current liabilities	(98)	(173)
Total adjustments	412	300
Net cash provided by operating activities	1,382	1,236
Investing activities:
Capital expenditures	(57)	(33)
Capitalized software development costs	(77)	(75)
Cash paid for acquisitions	(352)	(405)
Return of capital from equity method investment	44	0
Purchases of equity investments	0	(305)
Proceeds from investments, net	40	0
Net cash used in investing activities	(402)	(818)
Financing activities:
Proceeds from commercial paper, net of repayments	347	812
Repurchases of common stock	(780)	(759)
Dividends to stockholders	(312)	(279)
Payments relating to treasury shares received for restricted stock tax payments and stock option exercises	(60)	(76)
Other	23	1
Net cash used in financing activities	(782)	(301)
Effect of exchange rate changes on cash, cash equivalents and restricted cash and cash equivalents	1	(5)
Net increase in cash, cash equivalents, and restricted cash and cash equivalents	199	112
Cash, cash equivalents, and restricted cash and cash equivalents, beginning of period	1,872	1,568
Cash, cash equivalents, and restricted cash and cash equivalents, end of period	2,071	1,680
Supplemental cash flow disclosure:
Cash paid for income taxes	296	346
Cash paid for interest	$ 145	$ 104