Loans (Details 6) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Summary of the company's impaired loans
Total	$ 541,409	$ 535,487
Specific Allowance for Impairment	2,664	3,841
Allowance for Performing Loans	7,915	6,807
Pass [Member]
Summary of the company's impaired loans
Total	485,814	455,372
Special Mention [Member]
Summary of the company's impaired loans
Total	11,930	13,511
Impaired Loans Substandard [Member]
Summary of the company's impaired loans
Total	43,633	66,604
Impaired Loans Doubtful [Member]
Summary of the company's impaired loans
Total	32
One-to-four family mortgages [Member]
Summary of the company's impaired loans
Total	160,171	162,335
Specific Allowance for Impairment	791	754
Allowance for Performing Loans	2,357	1,736
One-to-four family mortgages [Member] | Pass [Member]
Summary of the company's impaired loans
Total	155,940	156,961
One-to-four family mortgages [Member] | Special Mention [Member]
Summary of the company's impaired loans
Total	654	779
One-to-four family mortgages [Member] | Impaired Loans Substandard [Member]
Summary of the company's impaired loans
Total	3,545	4,595
One-to-four family mortgages [Member] | Impaired Loans Doubtful [Member]
Summary of the company's impaired loans
Total	32
Home equity line of credit [Member]
Summary of the company's impaired loans
Total	35,822	37,083
Specific Allowance for Impairment	144	76
Allowance for Performing Loans	334	298
Home equity line of credit [Member] | Pass [Member]
Summary of the company's impaired loans
Total	34,934	34,737
Home equity line of credit [Member] | Special Mention [Member]
Summary of the company's impaired loans
Total		1,109
Home equity line of credit [Member] | Impaired Loans Substandard [Member]
Summary of the company's impaired loans
Total	888	1,237
Home equity line of credit [Member] | Impaired Loans Doubtful [Member]
Summary of the company's impaired loans
Total
Junior liens [Member]
Summary of the company's impaired loans
Total	4,188	4,336
Specific Allowance for Impairment	70	188
Allowance for Performing Loans	48	42
Junior liens [Member] | Pass [Member]
Summary of the company's impaired loans
Total	3,688	3,821
Junior liens [Member] | Special Mention [Member]
Summary of the company's impaired loans
Total	45	47
Junior liens [Member] | Impaired Loans Substandard [Member]
Summary of the company's impaired loans
Total	455	468
Junior liens [Member] | Impaired Loans Doubtful [Member]
Summary of the company's impaired loans
Total
Multi-family [Member]
Summary of the company's impaired loans
Total	33,010	33,056
Specific Allowance for Impairment		38
Allowance for Performing Loans	500	486
Multi-family [Member] | Pass [Member]
Summary of the company's impaired loans
Total	31,144	27,463
Multi-family [Member] | Special Mention [Member]
Summary of the company's impaired loans
Total		1,478
Multi-family [Member] | Impaired Loans Substandard [Member]
Summary of the company's impaired loans
Total	1,866	4,115
Multi-family [Member] | Impaired Loans Doubtful [Member]
Summary of the company's impaired loans
Total
Construction [Member]
Summary of the company's impaired loans
Total	14,548	18,900
Allowance for Performing Loans	131	256
Construction [Member] | Pass [Member]
Summary of the company's impaired loans
Total	10,436	14,052
Construction [Member] | Impaired Loans Substandard [Member]
Summary of the company's impaired loans
Total	4,112	4,848
Construction [Member] | Impaired Loans Doubtful [Member]
Summary of the company's impaired loans
Total
Land [Member]
Summary of the company's impaired loans
Total	42,280	45,906
Specific Allowance for Impairment	946	932
Allowance for Performing Loans	508	1,252
Land [Member] | Pass [Member]
Summary of the company's impaired loans
Total	14,644	14,374
Land [Member] | Special Mention [Member]
Summary of the company's impaired loans
Total	8,917	7,683
Land [Member] | Impaired Loans Substandard [Member]
Summary of the company's impaired loans
Total	18,719	23,849
Land [Member] | Impaired Loans Doubtful [Member]
Summary of the company's impaired loans
Total
Non-residential real estate [Member]
Summary of the company's impaired loans
Total	182,217	169,436
Specific Allowance for Impairment	117	1,240
Allowance for Performing Loans	2,108	1,681
Non-residential real estate [Member] | Pass [Member]
Summary of the company's impaired loans
Total	125,959	107,947
Non-residential real estate [Member] | Special Mention [Member]
Summary of the company's impaired loans
Total	1,489	669
Non-residential real estate [Member] | Impaired Loans Substandard [Member]
Summary of the company's impaired loans
Total	5,570	14,021
Non-residential real estate [Member] | Impaired Loans Doubtful [Member]
Summary of the company's impaired loans
Total
Farmland [Member]
Summary of the company's impaired loans
Total	49,199	46,799
Specific Allowance for Impairment	18	184
Allowance for Performing Loans	706	528
Farmland [Member] | Pass [Member]
Summary of the company's impaired loans
Total	44,072	38,496
Farmland [Member] | Special Mention [Member]
Summary of the company's impaired loans
Total	354	1,230
Farmland [Member] | Impaired Loans Substandard [Member]
Summary of the company's impaired loans
Total	4,773	7,073
Farmland [Member] | Impaired Loans Doubtful [Member]
Summary of the company's impaired loans
Total
Consumer loans [Member]
Summary of the company's impaired loans
Total	13,115	13,886
Specific Allowance for Impairment	56	121
Allowance for Performing Loans	435	217
Consumer loans [Member] | Pass [Member]
Summary of the company's impaired loans
Total	12,843	13,330
Consumer loans [Member] | Impaired Loans Substandard [Member]
Summary of the company's impaired loans
Total	272	556
Consumer loans [Member] | Impaired Loans Doubtful [Member]
Summary of the company's impaired loans
Total
Commercial loans [Member]
Summary of the company's impaired loans
Total	56,058	50,549
Specific Allowance for Impairment	522	308
Allowance for Performing Loans	788	311
Commercial loans [Member] | Pass [Member]
Summary of the company's impaired loans
Total	52,154	44,191
Commercial loans [Member] | Special Mention [Member]
Summary of the company's impaired loans
Total	471	516
Commercial loans [Member] | Impaired Loans Substandard [Member]
Summary of the company's impaired loans
Total	3,433	5,842
Commercial loans [Member] | Impaired Loans Doubtful [Member]
Summary of the company's impaired loans
Total