Loans (Details 6) (USD $) In Thousands, unless otherwise specified	Dec. 31, 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	$ 44,109	$ 123,056
Financing receivable, recorded investment, Loans past due over 90 days and still accruing	3,678	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	30,576	86,541
Financing receivable, recorded investment, Loans past due over 90 days and still accruing	3,678
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	7,466	27,104
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	4,842	6,581
Financing receivable, recorded investment, Loans past due over 90 days and still accruing		39
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	1,225	2,830
One-to four-family residential [Member] | 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	5,437	26,637
One-to four-family residential [Member] | 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	7,466	27,104
Multi-family residential [Member] | 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	2,027	5,860
Nonresidential [Member] | 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	17,065	42,902
Land [Member] | 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	6,047	11,142
Financing receivable, recorded investment, Loans past due over 90 days and still accruing	3,678
Multifamily and nonresidential [Member] | 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
Financing receivable, recorded investment, Loans past due over 90 days and still accruing
Home equity [Member] | 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	3,298	4,198
Financing receivable, recorded investment, Loans past due over 90 days and still accruing		39
Auto [Member] | 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	105	170
Marine [Member] | 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	176	479
Recreational vehicles [Member] | 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	1,259	1,725
Other [Member] | 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	4	9
Secured [Member] | 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	1,194	2,483
Unsecured [Member] | 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	$ 31	$ 347