Loans (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Dec. 31, 2010
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	$ 625,782	$ 670,497
Less allowance for loan losses	16,551	16,604	15,493
Net loans	609,231	653,893
Real Estate Loans - Construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	80,733	93,812
Less allowance for loan losses	6,392	7,182	5,774
Real Estate Loans - Single-family residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	249,167	267,051
Less allowance for loan losses	5,096	5,357	6,097
Real estate loans - Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	203,603	214,415
Less allowance for loan losses	1,537	1,731	1,409
Real Estate Loans - Multifamily and farmland [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	4,964	4,793
Less allowance for loan losses	13	13	17
Total real estate loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	538,467	580,071
Commercial (not secured by real estate) [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	60,358	60,646
Less allowance for loan losses	608	1,029	1,174
Farm loans (not secured by real estate) [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	12	0
Less allowance for loan losses	0	0
Consumer loans (not secured by real estate) [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	10,303	10,490
All other loans (not secured by real estate) [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	$ 16,642	$ 19,290

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 5

-Paragraph 8, 9

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (b)(1)(ii)

-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.7(d))

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher OTS

-Name Federal Regulation (FR)

-Number Title 12

-Section 563c.102

-Paragraph 8

-Subparagraph a(ii)

-Chapter V

-Subsection I

-LegacyDoc This is a non-GAAP reference that was included in the 2009 taxonomy. It will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 7

-Subparagraph d

-Article 9

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 114

-Paragraph 20

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 6

-Section L

-Subsection 1

+ Details

- Definition

Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

+ References+ Details

- Definition

Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

+ References+ Details