Loan Receivable and Allowance for Loan and Lease Losses Impaired loans (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended		12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Mar. 31, 2013
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	$ 12,720		$ 15,315
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	14,173		16,840
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	13,282	14,534	13,754
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	71	277	381
Impaired Financing Receivable, with Related Allowance, Recorded Investment	11,068		15,707
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	11,406		16,450
Impaired Financing Receivable, Related Allowance	1,351		2,311
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	12,702	14,718	16,597
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	81	342	444
Impaired Financing Receivable, Recorded Investment	23,788		31,022
Impaired Financing Receivable, Unpaid Principal Balance	25,579		33,290
Impaired Financing Receivable, Average Recorded Investment	25,984	29,252	30,351
Impaired Financing Receivable, Interest Income, Accrual Method	152	619	825
One- to four family loans [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	918		1,319
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	1,278		1,460
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	1,376	467	1,215
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	1	27	47
Impaired Financing Receivable, with Related Allowance, Recorded Investment	5,168		5,049
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	5,292		5,244
Impaired Financing Receivable, Related Allowance	667		317
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	5,200	2,552	5,363
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	40	28	57
Impaired Financing Receivable, Recorded Investment	6,086		6,368
Impaired Financing Receivable, Unpaid Principal Balance	6,570		6,704
Impaired Financing Receivable, Average Recorded Investment	6,576	3,019	6,578
Impaired Financing Receivable, Interest Income, Accrual Method	41	55	104
Multifamily Loans [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	1,374		616
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	1,374		616
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	995	97	308
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	1	5	5
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0
Impaired Financing Receivable, Related Allowance	0		0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	742
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0
Impaired Financing Receivable, Recorded Investment	1,374		616
Impaired Financing Receivable, Unpaid Principal Balance	1,374		616
Impaired Financing Receivable, Average Recorded Investment	995	839	308
Impaired Financing Receivable, Interest Income, Accrual Method	1	5	5
Commercial Real Estate Other Receivable [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	8,623		11,070
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	9,018		11,270
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	8,703	6,141	9,865
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	62	151	235
Impaired Financing Receivable, with Related Allowance, Recorded Investment	3,045		5,365
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	3,259		5,913
Impaired Financing Receivable, Related Allowance	229		194
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	3,802	8,182	6,302
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	5	115	133
Impaired Financing Receivable, Recorded Investment	11,668		16,435
Impaired Financing Receivable, Unpaid Principal Balance	12,277		17,183
Impaired Financing Receivable, Average Recorded Investment	12,505	14,323	16,167
Impaired Financing Receivable, Interest Income, Accrual Method	67	266	368
Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	75		1,230
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	339		1,492
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	519	5,293	1,230
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	53	53
Impaired Financing Receivable, Related Allowance	0		0
Impaired Financing Receivable, Recorded Investment	75		1,230
Impaired Financing Receivable, Unpaid Principal Balance	339		1,492
Impaired Financing Receivable, Average Recorded Investment	519	5,293	1,230
Impaired Financing Receivable, Interest Income, Accrual Method	0	53	53
Business [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	1,730		1,080
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	2,164		2,002
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	1,689	2,536	1,136
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	7	41	41
Impaired Financing Receivable, with Related Allowance, Recorded Investment	2,855		5,293
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	2,855		5,293
Impaired Financing Receivable, Related Allowance	455		1,800
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	3,700	3,242	4,932
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	36	199	254
Impaired Financing Receivable, Recorded Investment	4,585		6,373
Impaired Financing Receivable, Unpaid Principal Balance	5,019		7,295
Impaired Financing Receivable, Average Recorded Investment	5,389	5,778	6,068
Impaired Financing Receivable, Interest Income, Accrual Method	$ 43	$ 240	$ 295