Fair Value of Financial Instruments (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended		12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Fair Value of Financial Instruments
Cost to assume off-balance sheet commitments and standby letters of credit as a percentage of notional amount	10.00%
Assets:
Securities available for sale	$ 282,846	$ 114,250	$ 84,066
Accrued interest receivable	5,629	3,933	4,126
Off-balance sheet commitments and standby letters of credit
Notional Amount	333,592	152,057	131,450
Cost to Cede or Assume	33,359	15,206	13,145
Level 1
Assets:
Cash and cash equivalents	61,419	58,243	59,352
Securities available for sale	187,961	54,099	81,042
Federal Reserve Bank, TIB and FHLB stock, at cost	10,827	12,191	11,247
Accrued interest receivable	5,629	3,933	4,126
Liabilities:
Deposit accounts	998,217	476,852	548,101
FHLB advances	35,000	47,000	87,000
Accrued interest payable	195	213	142
Level 2
Assets:
Securities available for sale	94,885	59,190	2,072
Loans held for sale, net	3,176	4,728	3,681
Liabilities:
Deposit accounts	284,403	422,036	363,382
Other borrowings	53,435	32,360	31,267
Subordinated debentures	4,766	8,222	4,973
Off-balance sheet commitments and standby letters of credit
Cost to Cede or Assume	33,359	15,206	13,145
Level 3
Assets:
Securities available for sale		961	952
Loans held for investment, net	1,225,352	931,640	1,049,589
Carrying Amount
Assets:
Cash and cash equivalents	61,419	58,243	59,352
Securities available for sale	282,846	114,250	84,066
Federal Reserve Bank, TIB and FHLB stock, at cost	10,827	12,191	11,247
Loans held for sale, net	3,176	4,728	3,681
Loans held for investment, net	1,130,975	851,715	974,213
Accrued interest receivable	5,629	3,933	4,126
Liabilities:
Deposit accounts	1,284,134	895,870	904,768
FHLB advances	35,000	47,000	87,000
Other borrowings	51,474	28,500	28,500
Subordinated debentures	10,310	10,310	10,310
Accrued interest payable	195	213	142
Estimated Fair Value
Assets:
Cash and cash equivalents	61,419	58,243	59,352
Securities available for sale	282,846	114,250	84,066
Federal Reserve Bank, TIB and FHLB stock, at cost	10,827	12,191	11,247
Loans held for sale, net	3,176	4,728	3,681
Loans held for investment, net	1,225,352	931,640	1,049,589
Accrued interest receivable	5,629	3,933	4,126
Liabilities:
Deposit accounts	1,282,620	898,888	911,483
FHLB advances	35,000	47,000	87,000
Other borrowings	53,435	32,360	31,267
Subordinated debentures	4,766	8,222	4,973
Accrued interest payable	$ 195	$ 213	$ 142