Components Of Equity - Additional Information (Detail) (USD $)	0 Months Ended		6 Months Ended
	May 07, 2014	May 01, 2013	Jun. 30, 2014 Non-Discretionary Plan	Jun. 30, 2014 Discretionary Plan
Class of Stock [Line Items]
Shares repurchased			651,982	7,947,500
Average price per share			$ 44.26	$ 41.43
Expected common stock shares issued and outstanding				190,000,000
Date of declaration of dividends	May 07, 2014	May 01, 2013
Dividend declared per share	$ 0.32	$ 0.30
Date of dividend payment	Jun. 16, 2014	Jun. 17, 2013
Dividends payable to shareholders date of record	Jun. 02, 2014	Jun. 03, 2013