Regulatory Capital - Additional Information (Detail)	Mar. 31, 2013		Mar. 31, 2012
Regulatory Authorities [Line Items]
Ratio of total risk-based capital for adequately capitalized	8.00%	[1]	8.00%	[1]
Ratio of total risk-based capital for Cease and Desist Order	12.00%	[1]	12.00%	[1]

[1] Total risk-based capital divided by total risk-weighted assets.