Restructuring (Details) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) position	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($) position
S&P Global Ratings
Restructuring Cost and Reserve [Line Items]
Initial Charge Recorded	$ 6	$ 8	$ 6	$ 8
S&P Global Market Intelligence
Restructuring Cost and Reserve [Line Items]
Initial Charge Recorded		12		12
S&P Global Platts
Restructuring Cost and Reserve [Line Items]
Initial Charge Recorded		$ 1		$ 1
2015 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Workforce reduction (in positions) | position			70		550
Initial Charge Recorded			$ 63
Ending Reserve Balance	30		30		$ 50
Restructuring charges paid			20
2015 Restructuring Plan | S&P Global Ratings
Restructuring Cost and Reserve [Line Items]
Initial Charge Recorded			18
Ending Reserve Balance	9		9
2015 Restructuring Plan | S&P Global Market Intelligence
Restructuring Cost and Reserve [Line Items]
Initial Charge Recorded			31
Ending Reserve Balance	13		13
2015 Restructuring Plan | S&P Global Platts
Restructuring Cost and Reserve [Line Items]
Initial Charge Recorded			3
Ending Reserve Balance	1		1
2015 Restructuring Plan | Corporate
Restructuring Cost and Reserve [Line Items]
Initial Charge Recorded			11
Ending Reserve Balance	7		7
2016 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Initial Charge Recorded			11
Ending Reserve Balance	10		10
Restructuring charges paid			1
2016 Restructuring Plan | S&P Global Ratings
Restructuring Cost and Reserve [Line Items]
Initial Charge Recorded			8
Ending Reserve Balance	7		7
2016 Restructuring Plan | S&P Global Market Intelligence
Restructuring Cost and Reserve [Line Items]
Initial Charge Recorded			0
Ending Reserve Balance	0		0
2016 Restructuring Plan | S&P Global Platts
Restructuring Cost and Reserve [Line Items]
Initial Charge Recorded			3
Ending Reserve Balance	3		3
2016 Restructuring Plan | Corporate
Restructuring Cost and Reserve [Line Items]
Initial Charge Recorded			0
Ending Reserve Balance	$ 0		$ 0