Summary of Net OREO Expenses (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2013		Mar. 31, 2012		Mar. 31, 2011
Real Estate Properties [Line Items]
Valuation adjustments	$ 26,733	[1]	$ 15,338	[1]	$ 15,125
Foreclosure cost expense	2,602		4,387		5,586
Expenses from operations, net	8,236		8,959		10,215
OREO expense, net	$ 37,571		$ 28,684		$ 30,926

[1] Includes adjustments to the OREO reserve for probable losses.