Treasury Stock - Additional Information (Detail)	9 Months Ended			9 Months Ended		9 Months Ended
	Nov. 30, 2012	Nov. 30, 2012 September 2011 authorization	Sep. 14, 2011 September 2011 authorization	Nov. 30, 2012 October 2011 plan	Oct. 10, 2011 October 2011 plan	Nov. 30, 2012 July 2012 plan	Oct. 10, 2011 July 2012 plan	Nov. 30, 2012 September 2012 authorization
Equity, Class of Treasury Stock [Line Items]
Common stock authorized to be repurchased			1,000,000		1,000,000		551,853
Common stock repurchased	283,388	283,388		96,011		187,377
Common stock available for repurchase		364,476						1,000,000
Stock repurchase program, expiration date					Jul. 16, 2012		Feb. 15, 2013