Declared and Paid Dividends (Detail) (USD $)	12 Months Ended
	Feb. 28, 2014
Dividend Payment 1st
Dividends Payable [Line Items]
Date Declared	Jan. 06, 2011
Date Paid	Feb. 15, 2011
Dividend Amount	$ 0.04
Dividend Payment 2nd
Dividends Payable [Line Items]
Date Declared	Jan. 21, 2011
Date Paid	Mar. 15, 2011
Dividend Amount	$ 0.20
Dividend Payment 3rd
Dividends Payable [Line Items]
Date Declared	May 04, 2011
Date Paid	Jun. 15, 2011
Dividend Amount	$ 0.20
Dividend Payment 4th
Dividends Payable [Line Items]
Date Declared	Aug. 11, 2011
Date Paid	Sep. 15, 2011
Dividend Amount	$ 0.20
Dividend Payment 5th
Dividends Payable [Line Items]
Date Declared	Nov. 23, 2011
Date Paid	Dec. 15, 2011
Dividend Amount	$ 0.20
Dividend Payment 6th
Dividends Payable [Line Items]
Date Declared	Feb. 27, 2012
Date Paid	Mar. 15, 2012
Dividend Amount	$ 0.10
Dividevd Payment 7th
Dividends Payable [Line Items]
Date Declared	Mar. 23, 2012
Date Paid	Jun. 15, 2012
Dividend Amount	$ 0.10
Dividend Payment 8th
Dividends Payable [Line Items]
Date Declared	Aug. 08, 2012
Date Paid	Sep. 26, 2012
Dividend Amount	$ 0.10
Dividend Payment 9th
Dividends Payable [Line Items]
Date Declared	Dec. 03, 2012
Date Paid	Dec. 17, 2012
Dividend Amount	$ 0.10
Dividend Payment 10th
Dividends Payable [Line Items]
Date Declared	Feb. 25, 2013
Date Paid	Mar. 15, 2013
Dividend Amount	$ 0.10
Dividend Payment 11th
Dividends Payable [Line Items]
Date Declared	Jun. 04, 2013
Date Paid	Jun. 15, 2013
Dividend Amount	$ 0.05
Dividend Payment 12th
Dividends Payable [Line Items]
Date Declared	Sep. 06, 2013
Date Paid	Sep. 17, 2013
Dividend Amount	$ 0.05
Dividend Payment 13th
Dividends Payable [Line Items]
Date Declared	Dec. 17, 2013
Date Paid	Jan. 03, 2014
Dividend Amount	$ 0.05
Dividend Payment 14th
Dividends Payable [Line Items]
Date Declared	Mar. 04, 2014
Date Paid	Mar. 18, 2014
Dividend Amount	$ 0.05