Fair Value of Financial Instruments Fair Value Estimates (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Assets:
Securities available for sale	$ 291,147	$ 201,638	$ 282,202
Accrued interest receivable	9,083	7,131	6,762
Other real estate owned	711	1,037	752
Level 1
Assets:
Cash and cash equivalents	102,761	110,925	103,631
Securities available for sale	0	0	0
FHLB, FRB, and other stock, at cost	0	17,067	18,643
Loans held for investment, net	0	0	0
Accrued interest receivable	9,083	7,131	6,762
Other real estate owned	0	0	0
Liabilities:
Deposit accounts	1,634,484	1,216,847	1,157,972
FHLB advances	0	70,025	149,999
Other borrowings	0	0	0
Subordinated debentures	0	0	0
Accrued interest payable	216	209	177
Level 2
Assets:
Cash and cash equivalents	0	0	0
Securities available for sale	291,147	201,638	282,202
FHLB, FRB, and other stock, at cost	22,490	0	0
Loans held for investment, net	0	0	0
Accrued interest receivable	0	0	0
Other real estate owned	0	0	0
Liabilities:
Deposit accounts	506,063	519,898	371,574
FHLB advances	144,252	0	0
Other borrowings	47,043	48,312	46,095
Subordinated debentures	69,092	33,456	34,142
Accrued interest payable	0	0	0
Level 3
Assets:
Cash and cash equivalents	0	0	0
Securities available for sale	0	0	0
FHLB, FRB, and other stock, at cost	0	0	0
Loans held for investment, net	2,240,308	1,686,046	1,521,466
Accrued interest receivable	0	0	0
Other real estate owned	711	1,037	752
Liabilities:
Deposit accounts	0	0	0
FHLB advances	0	0	0
Other borrowings	0	0	0
Subordinated debentures	0	0	0
Accrued interest payable	0	0	0
Recurring basis
Assets:
Securities available for sale	291,147		282,202
Recurring basis | Level 1
Assets:
Securities available for sale	0		0
Recurring basis | Level 2
Assets:
Securities available for sale	291,147		282,202
Recurring basis | Level 3
Assets:
Securities available for sale	0		0
Carrying Amount
Assets:
Cash and cash equivalents	102,761	110,925	103,631
Securities available for sale	291,147	201,638	282,202
FHLB, FRB, and other stock, at cost	22,490	17,067	18,643
Loans held for investment, net	2,151,711	1,616,422	1,537,237
Accrued interest receivable	9,083	7,131	6,762
Other real estate owned	711	1,037	752
Liabilities:
Deposit accounts	2,139,207	1,630,826	1,543,466
FHLB advances	144,000	70,000	150,000
Other borrowings	47,483	46,643	45,561
Subordinated debentures	70,310	70,310	70,310
Accrued interest payable	216	209	177
Estimated Fair Value
Assets:
Cash and cash equivalents	102,761	110,925	103,631
Securities available for sale	291,147	201,638	282,202
FHLB, FRB, and other stock, at cost	22,490	17,067	18,643
Loans held for investment, net	2,240,308	1,686,046	1,521,466
Accrued interest receivable	9,083	7,131	6,762
Other real estate owned	711	1,037	752
Liabilities:
Deposit accounts	2,140,547	1,736,745	1,529,546
FHLB advances	144,252	70,025	149,999
Other borrowings	47,043	48,312	46,095
Subordinated debentures	69,092	33,456	34,142
Accrued interest payable	$ 216	$ 209	$ 177