Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating activities:
Net income	$ 1,960	$ 2,020	$ 2,554
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	662	586	535
Stock-based compensation	139	130	135
Deferred taxes	(33)	27	(654)
Cetip realized investment gain, net	0	0	(114)
Trayport gain, net	0	0	(110)
Gain on acquisition of remaining MERS interest	0	(110)	0
Other	(40)	(24)	(22)
Changes in assets and liabilities:
Customer accounts receivable	(30)	(44)	(135)
Other current and non-current assets	(17)	(45)	(24)
Section 31 fees payable	34	(33)	(2)
Deferred revenue	(18)	1	8
Other current and non-current liabilities	2	25	(86)
Total adjustments	699	513	(469)
Net cash provided by operating activities	2,659	2,533	2,085
Investing activities:
Capital expenditures	(153)	(134)	(220)
Capitalized software development costs	(152)	(146)	(137)
Proceeds from sale of Cetip, net	0	0	438
Cash paid for acquisitions, net of cash acquired	(352)	(1,246)	(423)
Return of capital from equity method investment	60	0	0
Cash received from divestitures	0	0	761
Purchases of equity investments	0	(306)	(327)
Proceeds from investments, net	9	77	0
Other	(6)	0	0
Net cash provided by (used in) investing activities	(594)	(1,755)	92
Financing activities:
Proceeds from debt facilities, net	10	2,213	984
Repayments of debt facilities	0	(600)	(850)
Proceeds from/(repayments of) commercial paper, net	360	(283)	(409)
Repurchases of common stock	(1,460)	(1,198)	(949)
Dividends to stockholders	(621)	(555)	(476)
Payments relating to treasury shares received for restricted stock tax payments and stock option exercises	(65)	(80)	(88)
Acquisition of non-controlling interest and redeemable non-controlling interest	0	(35)	(174)
Proceeds from issuance of redeemable non-controlling interest	0	71	0
Other	23	4	(9)
Net cash used in financing activities	(1,753)	(463)	(1,971)
Effect of exchange rate changes on cash, cash equivalents, and restricted cash and cash equivalents	4	(11)	12
Net increase in cash, cash equivalents, and restricted cash and cash equivalents	316	304	218
Cash, cash equivalents, and restricted cash and cash equivalents at beginning of year	1,872	1,568	1,350
Cash, cash equivalents, and restricted cash and cash equivalents at end of year	2,188	1,872	1,568
Supplemental cash flow disclosures:
Cash paid for income taxes	557	533	594
Cash paid for interest	$ 280	$ 202	$ 171