Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Activities:
Net income	$ 1,638	$ 2,228	$ 1,268
Adjustments to reconcile net income to cash provided by operating activities from continuing operations:
Depreciation	82	85	90
Amortization of intangibles	98	96	67
Provision for losses on accounts receivable	16	9	8
Deferred income taxes	0	79	280
Stock-based compensation	99	76	78
Gain on dispositions	0	(1,101)	(11)
Accrued legal and regulatory settlements	55	54	119
Other	96	30	57
Changes in operating assets and liabilities, net of effect of acquisitions and dispositions:
Accounts receivable	(196)	(177)	(118)
Prepaid and other current assets	10	5	5
Accounts payable and accrued expenses	75	19	(9)
Unearned revenue	85	107	129
Accrued legal and regulatory settlements	(4)	(150)	(1,624)
Other current liabilities	(85)	(19)	(77)
Net change in prepaid/accrued income taxes	32	174	129
Net change in other assets and liabilities	15	45	(35)
Cash provided by operating activities from continuing operations	2,016	1,560	356
Investing Activities:
Capital expenditures	(123)	(115)	(139)
Acquisitions, net of cash acquired	(83)	(177)	(2,396)
Proceeds from dispositions	2	1,498	14
Changes in short-term investments	(5)	(1)	(4)
Cash (used for) provided by investing activities from continuing operations	(209)	1,205	(2,525)
Financing Activities:
(Payments on)/additions to short-term debt, net	0	(143)	143
Proceeds from issuance of senior notes, net	0	493	2,674
Payments on senior notes	0	(421)	0
Dividends paid to shareholders	(421)	(380)	(363)
Distributions to noncontrolling interest holders	(111)	(116)	(104)
Repurchase of treasury shares	(1,001)	(1,123)	(974)
Exercise of stock options	75	88	86
Contingent consideration payments	0	(39)	(5)
Purchase of additional CRISIL shares	0	0	(16)
Employee withholding tax on share-based payments	(49)	(55)	(92)
Cash (used for) provided by financing activities from continuing operations	(1,507)	(1,696)	1,349
Effect of exchange rate changes on cash	87	(158)	(67)
Cash provided by continuing operations	387	911	(887)
Discontinued Operations:
Cash used for operating activities	0	0	(129)
Cash used for discontinued operations	0	0	(129)
Net change in cash and cash equivalents	387	911	(1,016)
Cash and cash equivalents at beginning of year	2,392	1,481	2,497
Cash and cash equivalents at end of year	2,779	2,392	1,481
Cash paid during the year for:
Interest (including discontinued operations)	139	150	65
Income taxes (including discontinued operations)	$ 709	$ 683	$ 260