Disclosures About Fair Value of Financial Instruments - Balance Sheet Grouping (Details 3) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale securities	$ 180,038us-gaap_AvailableForSaleSecurities	$ 187,565us-gaap_AvailableForSaleSecurities
Held-to-maturity securities	48,362	50,725
Loans held for sale	939	573
Loans held for investment	1,810,842	1,799,155	1,404,275
Real estate acquired by foreclosure	4,863	4,863
Level 1 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash and short term investments	129,108	68,923
Available-for-sale securities	30,084	27,035
Other securities	10,000	11,365
Loans held for sale	939	573
Total	170,131	107,896
Level 2 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale securities	149,954	160,530
Held-to-maturity securities	48,362	50,725
Total	198,316	211,255
Financial Liabilities:
Deposits	1,934,954	1,849,281
Securities sold under agreements to repurchase	13,012	4,605
Other borrowed funds	7,340	47,561
Total	1,955,306	1,901,447
Level 3 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Loans held for investment	1,799,619	1,788,454
Real estate acquired by foreclosure	4,863	4,863
Total	1,804,482	1,793,317
Carrying Value [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash and short term investments	129,108	68,923
Available-for-sale securities	180,038	187,565
Held-to-maturity securities	47,997	50,713
Other securities	10,000	11,365
Loans held for sale	939	573
Loans held for investment	1,810,842	1,799,155
Real estate acquired by foreclosure	4,863	4,863
Total	2,183,787	2,123,157
Financial Liabilities:
Deposits	1,931,851	1,845,713
Securities sold under agreements to repurchase	13,012	4,605
Other borrowed funds	7,323	47,586
Total	1,952,186	1,897,904
Fair Value [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash and short term investments	129,108	68,923
Available-for-sale securities	180,038	187,565
Held-to-maturity securities	48,362	50,725
Other securities	10,000	11,365
Loans held for sale	939	573
Loans held for investment	1,799,619	1,788,454
Real estate acquired by foreclosure	4,863	4,863
Total	2,172,929	2,112,468
Financial Liabilities:
Deposits	1,934,954	1,849,281
Securities sold under agreements to repurchase	13,012	4,605
Other borrowed funds	7,340	47,561
Total	$ 1,955,306	$ 1,901,447

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558

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-Publisher FASB

-Name Accounting Standards Codification

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-Section 50

-Paragraph 5

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-Name Accounting Standards Codification

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- Definition

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash

-URI http://asc.fasb.org/extlink&oid=6506951

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-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash Equivalents

-URI http://asc.fasb.org/extlink&oid=6507016

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- Definition

Fair value portion of investments accounted under the cost method.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 325

-SubTopic 20

-Section 25

-Paragraph 1

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Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 10

-Subparagraph (a)

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- Definition

Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.

+ References

No definition available.

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- Definition

Fair value of financial obligations, including, but not limited to, debt instruments, derivative liabilities, federal funds purchased and sold under agreements to repurchase, securities loaned or sold under agreements to repurchase, financial instruments sold not yet purchased, guarantees, line of credit, loans and notes payable, servicing liability, and trading liabilities.

+ References

No definition available.

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Fair value of investments in debt securities classified as held-to-maturity.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 5

-Subparagraph (aa)

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-Subparagraph (f)

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

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-Subparagraph (a)

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

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=28367877&loc=d3e4428-111522

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- Definition

The face amount of loans that will be sold to other entities.

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- Definition

Carrying amount as of the balance sheet date of land and buildings obtained through foreclosure proceedings or defeasance in full or partial satisfaction of a debt arrangement.

+ References

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-Publisher FASB

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-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=28367877&loc=d3e4437-111522

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 28

-Article 12

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-Number 210

-Section 04

-Paragraph c

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Fair value portion of securities that an entity sells and agrees to repurchase at a specified date for a specified price.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

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