Loan Receivable and Allowance for Loan and Lease Losses Impaired loans with an allowance recorded (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Mar. 31, 2012
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Interest Income, Cash Basis Method	$ 791	$ 1,519
Impaired Financing Receivable, Recorded Investment	29,678		36,247
Impaired Financing Receivable, Unpaid Principal Balance	32,867		39,309
Impaired Financing Receivable, Related Allowance	2,657		949
Impaired Financing Receivable, Average Recorded Investment	27,729	51,569
One- to four family loans [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Interest Income, Cash Basis Method	92	130
Impaired Financing Receivable, Recorded Investment	6,787		2,307
Impaired Financing Receivable, Unpaid Principal Balance	7,340		2,388
Impaired Financing Receivable, Related Allowance	379		207
Impaired Financing Receivable, Average Recorded Investment	4,856	9,347
Multifamily Loans [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Interest Income, Cash Basis Method	5	88
Impaired Financing Receivable, Recorded Investment	0		1,008
Impaired Financing Receivable, Unpaid Principal Balance	0		1,073
Impaired Financing Receivable, Related Allowance	0		61
Impaired Financing Receivable, Average Recorded Investment	339	4,623
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Interest Income, Cash Basis Method	346	235
Impaired Financing Receivable, Recorded Investment	15,899		20,773
Impaired Financing Receivable, Unpaid Principal Balance	17,334		21,372
Impaired Financing Receivable, Related Allowance	457		532
Impaired Financing Receivable, Average Recorded Investment	14,134	18,320
Construction Loans [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Interest Income, Cash Basis Method	53	804
Impaired Financing Receivable, Recorded Investment	1,230		6,087
Impaired Financing Receivable, Unpaid Principal Balance	1,492		7,283
Impaired Financing Receivable, Related Allowance	0		48
Impaired Financing Receivable, Average Recorded Investment	2,743	12,745
Commercial Loan [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Interest Income, Cash Basis Method	295	262
Impaired Financing Receivable, Recorded Investment	5,762		6,072
Impaired Financing Receivable, Unpaid Principal Balance	6,701		7,193
Impaired Financing Receivable, Related Allowance	1,821		101
Impaired Financing Receivable, Average Recorded Investment	5,657	6,534
Consumer Loan [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Interest Income, Cash Basis Method	0	0
Impaired Financing Receivable, Recorded Investment	0		0
Impaired Financing Receivable, Unpaid Principal Balance	0		0
Impaired Financing Receivable, Related Allowance	0		0
Impaired Financing Receivable, Average Recorded Investment	0	0
Loan impaired with allowance recorded [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Interest Income, Cash Basis Method	463	498
Impaired Financing Receivable, Recorded Investment	17,485		18,732
Impaired Financing Receivable, Unpaid Principal Balance	18,785		21,096
Impaired Financing Receivable, Related Allowance	2,657		949
Impaired Financing Receivable, Average Recorded Investment	15,861	27,914
One- to four family loans [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Interest Income, Cash Basis Method	54	91
Impaired Financing Receivable, Recorded Investment	5,676		1,679
Impaired Financing Receivable, Unpaid Principal Balance	6,229		1,760
Impaired Financing Receivable, Related Allowance	379		207
Impaired Financing Receivable, Average Recorded Investment	4,197	7,171
Multifamily Loans [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Interest Income, Cash Basis Method	0	70
Impaired Financing Receivable, Recorded Investment	0		814
Impaired Financing Receivable, Unpaid Principal Balance	0		879
Impaired Financing Receivable, Related Allowance	0		61
Impaired Financing Receivable, Average Recorded Investment	339	4,427
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Interest Income, Cash Basis Method	155	231
Impaired Financing Receivable, Recorded Investment	7,239		14,469
Impaired Financing Receivable, Unpaid Principal Balance	7,986		15,068
Impaired Financing Receivable, Related Allowance	457		532
Impaired Financing Receivable, Average Recorded Investment	6,732	12,118
Construction Loans [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Interest Income, Cash Basis Method	0	0
Impaired Financing Receivable, Recorded Investment	0		681
Impaired Financing Receivable, Unpaid Principal Balance	0		1,613
Impaired Financing Receivable, Related Allowance	0		48
Impaired Financing Receivable, Average Recorded Investment	0	2,606
Commercial Loan [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Interest Income, Cash Basis Method	254	106
Impaired Financing Receivable, Recorded Investment	4,570		1,089
Impaired Financing Receivable, Unpaid Principal Balance	4,570		1,776
Impaired Financing Receivable, Related Allowance	1,821		101
Impaired Financing Receivable, Average Recorded Investment	4,593	1,592
Consumer Loan [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Interest Income, Cash Basis Method	0	0
Impaired Financing Receivable, Recorded Investment	0		0
Impaired Financing Receivable, Unpaid Principal Balance	0		0
Impaired Financing Receivable, Related Allowance	0		0
Impaired Financing Receivable, Average Recorded Investment		$ 0