Components Of Equity - Additional Information (Detail) (Subsequent Event, USD $)	0 Months Ended
	May 01, 2013
Subsequent Event
Class of Stock [Line Items]
Date of declaration of dividends	May 01, 2013
Dividend declared per share	$ 0.30
Date of dividend payment	Jun. 17, 2013
Dividends payable to shareholders date of record	Jun. 03, 2013