Fair Value Measurement: Fair Value Measurements, Nonrecurring, Valuation Techniques (Details)	6 Months Ended
	Sep. 30, 2012
Impaired loans
Fair Value Measurements, Valuation Techniques	Appraised value
Significant unobservable inputs	Adjustment for market conditions
Real estate owned
Fair Value Measurements, Valuation Techniques	Appraised value
Significant unobservable inputs	Adjustment for market conditions
Minimum | Impaired loans
Market adjustment to appraisals	0.00%
Minimum | Real estate owned
Market adjustment to appraisals	0.00%
Maximum | Impaired loans
Market adjustment to appraisals	14.00%
Maximum | Real estate owned
Market adjustment to appraisals	14.00%