Loan Receivable and Allowance for Loan and Lease Losses Non-performing loans (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Mar. 31, 2012
Financing Receivable, Impaired [Line Items]
Loans and Leases Receivable, Impaired, Nonperforming, Nonaccrual of Interest	$ 39,635	$ 54,588
One- to four family loans [Member]
Financing Receivable, Impaired [Line Items]
Loans and Leases Receivable, Impaired, Nonperforming, Nonaccrual of Interest	7,363	6,988
Multifamily Loans [Member]
Financing Receivable, Impaired [Line Items]
Loans and Leases Receivable, Impaired, Nonperforming, Nonaccrual of Interest	1,790	2,923
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Loans and Leases Receivable, Impaired, Nonperforming, Nonaccrual of Interest	16,487	24,467
Construction Loans [Member]
Financing Receivable, Impaired [Line Items]
Loans and Leases Receivable, Impaired, Nonperforming, Nonaccrual of Interest	4,658	11,325
Commercial Loan [Member]
Financing Receivable, Impaired [Line Items]
Loans and Leases Receivable, Impaired, Nonperforming, Nonaccrual of Interest	9,337	8,862
Consumer Loan [Member]
Financing Receivable, Impaired [Line Items]
Loans and Leases Receivable, Impaired, Nonperforming, Nonaccrual of Interest	$ 0	$ 23