Impaired Loans and Valuation Allowance for Loan Losses (Details 5) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Sep. 30, 2011
Loan portfolio and related allowance
Individually Evaluated for Impairment, carrying value	$ 88,629	$ 105,407
Collectively Evaluated for Impairment, carrying value	1,113,849	1,103,141
Associated allowance for Credit Losses, Individually Evaluated for Impairment	8,518	8,704
Associated allowance for Credit Losses, Collectively Evaluated for Impairment	14,601	19,697
Financing Receivable, Carrying Value, Total	1,202,478	1,208,548
Financing Receivable Associated allowances, Total	23,119	28,401
Construction and Land Development [Member]
Loan portfolio and related allowance
Individually Evaluated for Impairment, carrying value	4,525	5,401
Collectively Evaluated for Impairment, carrying value	51,688	42,252
Associated allowance for Credit Losses, Individually Evaluated for Impairment	444	288
Associated allowance for Credit Losses, Collectively Evaluated for Impairment	835	1,544
Financing Receivable, Carrying Value, Total	56,213	47,653
Financing Receivable Associated allowances, Total	1,279	1,832
Commercial Real Estate [Member]
Loan portfolio and related allowance
Individually Evaluated for Impairment, carrying value	44,833	64,001
Collectively Evaluated for Impairment, carrying value	428,970	455,350
Associated allowance for Credit Losses, Individually Evaluated for Impairment	3,533	4,962
Associated allowance for Credit Losses, Collectively Evaluated for Impairment	6,880	8,545
Financing Receivable, Carrying Value, Total	473,803	519,351
Financing Receivable Associated allowances, Total	10,413	13,507
Residential Real Estate [Member]
Loan portfolio and related allowance
Individually Evaluated for Impairment, carrying value	38,281	34,609
Collectively Evaluated for Impairment, carrying value	524,140	501,316
Associated allowance for Credit Losses, Individually Evaluated for Impairment	4,440	3,277
Associated allowance for Credit Losses, Collectively Evaluated for Impairment	6,061	8,453
Financing Receivable, Carrying Value, Total	562,421	535,925
Financing Receivable Associated allowances, Total	10,501	11,730
Commercial and Financial [Member]
Loan portfolio and related allowance
Individually Evaluated for Impairment, carrying value	37	122
Collectively Evaluated for Impairment, carrying value	58,185	53,412
Associated allowance for Credit Losses, Individually Evaluated for Impairment	1	9
Associated allowance for Credit Losses, Collectively Evaluated for Impairment	334	385
Financing Receivable, Carrying Value, Total	58,222	53,534
Financing Receivable Associated allowances, Total	335	394
Consumer [Member]
Loan portfolio and related allowance
Individually Evaluated for Impairment, carrying value	953	1,274
Collectively Evaluated for Impairment, carrying value	50,866	50,811
Associated allowance for Credit Losses, Individually Evaluated for Impairment	100	168
Associated allowance for Credit Losses, Collectively Evaluated for Impairment	491	770
Financing Receivable, Carrying Value, Total	51,819	52,085
Financing Receivable Associated allowances, Total	$ 591	$ 938