Fair Value - Balance Sheet Grouping (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale securities	$ 191,451	$ 198,237
Held-to-maturity securities	53,196	56,588
Loans held for investment	1,504,998	1,359,415	1,270,559
Real estate acquired by foreclosure	4,863	6,690
Level 1 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash and short term investments	71,547	34,757
Available-for-sale securities	25,070	15,000
Other securities	11,006	7,730
Total	107,623	57,487
Level 2 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale securities	166,381	183,237
Held-to-maturity securities	53,196	56,588
Total	219,577	239,825
Financial Liabilities:
Deposits	1,581,313	1,452,900
Securities sold under agreements to repurchase	4,391	2,583
Other borrowed funds		46,895
Total	1,585,704	1,502,378
Level 3 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Loans held for investment	1,496,828	1,342,269
Real estate acquired by foreclosure	4,863	6,690
Total	1,501,691	1,348,959
Carrying Value [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash and short term investments	71,547	34,757
Available-for-sale securities	191,451	198,237
Held-to-maturity securities	53,308	57,278
Other securities	11,006	7,730
Loans held for investment	1,504,998	1,359,415
Real estate acquired by foreclosure	4,863	6,690
Total	1,837,173	1,664,107
Financial Liabilities:
Deposits	1,577,691	1,534,572
Securities sold under agreements to repurchase	4,391	5,617
Other borrowed funds		51,835
Total	1,582,082	1,592,024
Fair Value [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash and short term investments	71,547	34,757
Available-for-sale securities	191,451	198,237
Held-to-maturity securities	53,196	56,588
Other securities	11,006	7,730
Loans held for investment	1,496,828	1,342,269
Real estate acquired by foreclosure	4,863	6,690
Total	1,828,891	1,646,271
Financial Liabilities:
Deposits	1,581,313	1,452,900
Securities sold under agreements to repurchase	4,391	2,583
Other borrowed funds		46,895
Total	$ 1,585,704	$ 1,502,378