The cash outflow to reacquire common stock during the period.

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Total cost of shares repurchased divided by the total number of shares repurchased.

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Number of shares that have been repurchased during the period and are being held in treasury.

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Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

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Equity - Schedule of share repurchases (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	1 Months Ended	3 Months Ended		6 Months Ended
	Dec. 31, 2015	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total number of shares purchased	0.3	1.1	1.4	2.6	3.5
Average price paid per share (in dollars per share)		$ 137.49	$ 107.74	$ 133.01	$ 98.05
Total cash utilized	$ 26			$ 346
Cash used to repurchase shares				346	$ 373
Stock Repurchases
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cash used to repurchase shares				373
Total SPGI Equity
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total cash utilized		$ 145	$ 147	$ 346	$ 347