Loans - Portfolio by Type and Class (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	$ 1,982,280	$ 1,799,155	$ 1,504,998
Loans held for sale	192	573
Originated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	1,809,635	1,560,731
Loans held for sale	192	573
Acquired [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	172,645	238,424
Commercial & Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	820,337	788,410	725,583
Commercial & Industrial [Member] | Originated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	802,603	759,810
Commercial & Industrial [Member] | Acquired [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	17,734	28,600
Owner occupied commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	183,224	163,592	132,940
Owner occupied commercial real estate [Member] | Originated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	169,296	148,197
Owner occupied commercial real estate [Member] | Acquired [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	13,928	15,395
Commerical real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	483,628	339,006	308,700
Commerical real estate [Member] | Originated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	465,989	308,521
Commerical real estate [Member] | Acquired [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	17,639	30,485
Construction, land & land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	252,206	240,666	230,259
Construction, land & land development [Member] | Originated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	247,228	230,143
Construction, land & land development [Member] | Acquired [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	4,978	10,523
Residential mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	230,796	257,066	100,818
Residential mortgage [Member] | Originated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	114,733	107,275
Residential mortgage [Member] | Acquired [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	116,063	149,791
Consumer and other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	12,089	10,415	$ 6,698
Consumer and other [Member] | Originated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	9,786	6,785
Consumer and other [Member] | Acquired [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	$ 2,303	$ 3,630