Earning Per Share ("EPS") - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended		3 Months Ended				0 Months Ended		1 Months Ended	0 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014 Accelerated Share Repurchase Contract	Mar. 31, 2014 Accelerated Share Repurchase Contract	Mar. 31, 2014 Evergreen Program	Mar. 31, 2014 Share Repurchase Program	May 15, 2014 Accelerated Share Repurchase Contract Two	May 15, 2014 Accelerated Share Repurchase Contract Two	Jul. 31, 2014 Accelerated Share Repurchase Contract Two Subsequent Event	Jan. 29, 2014 Maximum
Equity, Class of Treasury Stock [Line Items]
Share repurchase program, authorized amount										$ 500
Accelerated share repurchase agreements, contract value				260	74	186		175
Payment for share repurchase	435.0	50.0		260.0			175.0
Stock purchases, shares			0.3	3.5			2.3		0.2
Remaining amount for share repurchase program	$ 139