Equity (Details) - USD ($)					1 Months Ended		3 Months Ended	4 Months Ended	12 Months Ended
	Jan. 27, 2016	Jun. 25, 2014	Jul. 25, 2013	Apr. 02, 2013	Dec. 31, 2015	Dec. 31, 2013	Mar. 31, 2013	Jul. 25, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2015	Dec. 04, 2013	Mar. 25, 2013	Dec. 31, 2011
Dividend history
Quarterly dividend rate (in usd per share)									$ 0.330	$ 0.3	$ 0.28
Annualized dividend rate (in usd per share)									$ 1.32	$ 1.2	$ 1.12
Dividends paid									$ 363,000,000	$ 326,000,000	$ 308,000,000
Share repurchases
Total number of shares purchased (in shares)			700,000	1,400,000	300,000		7,200,000	9,300,000
Average price paid per share (in dollars per share)					$ 98.98	$ 58.36			$ 99.00	$ 79.06	$ 58.52
Repurchase of treasury shares									$ 974,000,000	$ 362,000,000	$ 978,000,000
Total cash utilized					$ 26,000,000				1,002,000,000	346,000,000	989,000,000
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Balance as of December 31, 2014					920,000,000				920,000,000	810,000,000		$ 920,000,000
Net income attributable to noncontrolling interest									101,000,000
Distributions to noncontrolling interest									(98,000,000)		$ (22,000,000)
Redemption value adjustment									107,000,000
Balance as of December 31, 2015					$ 920,000,000				$ 920,000,000	$ 810,000,000
Stockholders' Equity Note [Abstract]
Preferred stock authorized (shares)												2,000,000
Par value of Preferred stock (in usd per share)												$ 1
Preferred stock issued (in shares)												0
Quarterly dividend rate (in usd per share)									$ 0.330	$ 0.3	$ 0.28
Authorized amount														$ 500,000,000
Volume weighted-average share price (in dollars per share)			$ 53.7995					$ 53.7995
Interest in joint venture minimum percentage									20.00%
Change in control period									15 days
2013 Repurchase Program [Member]
Share repurchases
Total number of shares purchased (in shares)									10,100,000	4,400,000	0
Stockholders' Equity Note [Abstract]
Stock repurchase program number of shares authorized to be repurchased (shares)													50,000,000
Maximum number of shares authorized for repurchase under stock repurchase plan as percentage of outstanding common stock													18.00%
Remaining shares available under repurchase program												35,500,000
2011 Repurchase Program [Member]
Share repurchases
Total number of shares purchased (in shares)						100,000			0	0	16,900,000
Total cash utilized						$ 10,000,000
Stockholders' Equity Note [Abstract]
Stock repurchase program number of shares authorized to be repurchased (shares)															50,000,000
Maximum number of shares authorized for repurchase under stock repurchase plan as percentage of outstanding common stock															17.00%
Remaining shares available under repurchase program												0
Stock Repurchases [Member]
Share repurchases
Repurchase of treasury shares									$ 974,000,000	$ 362,000,000
Total cash utilized									$ 1,000,000,000	$ 352,000,000	$ 989,000,000
Harold W. McGraw III [Member]
Share repurchases
Total number of shares purchased (in shares)		500,000
Average price paid per share (in dollars per share)		$ 82.66
Total cash utilized		$ 41,000,000
Repurchase discount		0.35%
Subsequent Event [Member]
Dividend history
Quarterly dividend rate (in usd per share)	$ 0.36
Stockholders' Equity Note [Abstract]
Quarterly dividend rate (in usd per share)	$ 0.36