Loans - Portfolio by Type and Class (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	$ 1,504,998	$ 1,359,415	$ 1,270,559
Originated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	1,492,632	1,336,017
Acquired [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	12,366	23,398
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	1,397,482	1,245,329
Commercial [Member] | Originated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	1,385,727	1,222,833
Commercial [Member] | Acquired [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	11,755	22,496
Commercial & Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	725,583	681,290	635,951
Commercial & Industrial [Member] | Originated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	723,794	674,621
Commercial & Industrial [Member] | Acquired [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	1,789	6,669
Owner occupied commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	132,940	156,961	147,521
Owner occupied commercial real estate [Member] | Originated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	131,171	153,507
Owner occupied commercial real estate [Member] | Acquired [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	1,769	3,454
Commerical real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	308,700	267,011	238,053
Commerical real estate [Member] | Originated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	300,659	254,838
Commerical real estate [Member] | Acquired [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	8,041	12,173
Construction, land & land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	230,259	140,067	141,927
Construction, land & land development [Member] | Originated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	230,103	139,867
Construction, land & land development [Member] | Acquired [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	156	200
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	107,516	114,086
Consumer [Member] | Originated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	106,905	113,184
Consumer [Member] | Acquired [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	611	902
Residential mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	100,818	106,362	99,283
Residential mortgage [Member] | Originated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	100,446	105,888
Residential mortgage [Member] | Acquired [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	372	474
Other consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	6,698	7,724	7,824
Other consumer [Member] | Originated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	6,459	7,296
Other consumer [Member] | Acquired [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	$ 239	$ 428