Loans (Details 5) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Presentation of recorded investment in nonaccrual loans and loans past due over 90 days and still on accrual by class of loans
Financing receivable, recorded investment, Nonaccrual	$ 114,482	$ 123,056
Financing receivable, recorded investment, Loans past due over 90 days and still accruing	47	39
Permanent Real Estate Loans [Member]
Presentation of recorded investment in nonaccrual loans and loans past due over 90 days and still on accrual by class of loans
Financing receivable, recorded investment, Nonaccrual	87,706	86,541
Financing receivable, recorded investment, Loans past due over 90 days and still accruing
Permanent Real Estate Loans [Member] | One-to four-family residential [Member]
Presentation of recorded investment in nonaccrual loans and loans past due over 90 days and still on accrual by class of loans
Financing receivable, recorded investment, Nonaccrual	26,705	26,637
Financing receivable, recorded investment, Loans past due over 90 days and still accruing
Permanent Real Estate Loans [Member] | Multifamily residential [Member]
Presentation of recorded investment in nonaccrual loans and loans past due over 90 days and still on accrual by class of loans
Financing receivable, recorded investment, Nonaccrual	9,582	5,860
Financing receivable, recorded investment, Loans past due over 90 days and still accruing
Permanent Real Estate Loans [Member] | Nonresidential [Member]
Presentation of recorded investment in nonaccrual loans and loans past due over 90 days and still on accrual by class of loans
Financing receivable, recorded investment, Nonaccrual	430,103	42,902
Financing receivable, recorded investment, Loans past due over 90 days and still accruing
Permanent Real Estate Loans [Member] | Land [Member]
Presentation of recorded investment in nonaccrual loans and loans past due over 90 days and still on accrual by class of loans
Financing receivable, recorded investment, Nonaccrual	8,316	11,142
Financing receivable, recorded investment, Loans past due over 90 days and still accruing
Construction Loans [Member]
Presentation of recorded investment in nonaccrual loans and loans past due over 90 days and still on accrual by class of loans
Financing receivable, recorded investment, Nonaccrual	18,335	27,104
Financing receivable, recorded investment, Loans past due over 90 days and still accruing
Construction Loans [Member] | One-to four-family residential [Member]
Presentation of recorded investment in nonaccrual loans and loans past due over 90 days and still on accrual by class of loans
Financing receivable, recorded investment, Nonaccrual	18,335	27,104
Financing receivable, recorded investment, Loans past due over 90 days and still accruing
Construction Loans [Member] | Multifamily and nonresidential construction [Member]
Presentation of recorded investment in nonaccrual loans and loans past due over 90 days and still on accrual by class of loans
Financing receivable, recorded investment, Nonaccrual
Financing receivable, recorded investment, Loans past due over 90 days and still accruing
Consumer Loans [Member]
Presentation of recorded investment in nonaccrual loans and loans past due over 90 days and still on accrual by class of loans
Financing receivable, recorded investment, Nonaccrual	6,655	6,581
Financing receivable, recorded investment, Loans past due over 90 days and still accruing	47	39
Consumer Loans [Member] | Home Equity [Member]
Presentation of recorded investment in nonaccrual loans and loans past due over 90 days and still on accrual by class of loans
Financing receivable, recorded investment, Nonaccrual	4,897	4,198
Financing receivable, recorded investment, Loans past due over 90 days and still accruing	47	39
Consumer Loans [Member] | Auto [Member]
Presentation of recorded investment in nonaccrual loans and loans past due over 90 days and still on accrual by class of loans
Financing receivable, recorded investment, Nonaccrual	101	170
Financing receivable, recorded investment, Loans past due over 90 days and still accruing
Consumer Loans [Member] | Marine [Member]
Presentation of recorded investment in nonaccrual loans and loans past due over 90 days and still on accrual by class of loans
Financing receivable, recorded investment, Nonaccrual	342	479
Financing receivable, recorded investment, Loans past due over 90 days and still accruing
Consumer Loans [Member] | Recreational vehicle [Member]
Presentation of recorded investment in nonaccrual loans and loans past due over 90 days and still on accrual by class of loans
Financing receivable, recorded investment, Nonaccrual	1,293	1,725
Financing receivable, recorded investment, Loans past due over 90 days and still accruing
Consumer Loans [Member] | Other [Member]
Presentation of recorded investment in nonaccrual loans and loans past due over 90 days and still on accrual by class of loans
Financing receivable, recorded investment, Nonaccrual	22	9
Financing receivable, recorded investment, Loans past due over 90 days and still accruing
Commercial Loans [Member]
Presentation of recorded investment in nonaccrual loans and loans past due over 90 days and still on accrual by class of loans
Financing receivable, recorded investment, Nonaccrual	1,786	2,830
Financing receivable, recorded investment, Loans past due over 90 days and still accruing
Commercial Loans [Member] | Secured [Member]
Presentation of recorded investment in nonaccrual loans and loans past due over 90 days and still on accrual by class of loans
Financing receivable, recorded investment, Nonaccrual	1,350	2,483
Financing receivable, recorded investment, Loans past due over 90 days and still accruing
Commercial Loans [Member] | Unsecured [Member]
Presentation of recorded investment in nonaccrual loans and loans past due over 90 days and still on accrual by class of loans
Financing receivable, recorded investment, Nonaccrual	436	347
Financing receivable, recorded investment, Loans past due over 90 days and still accruing