Loans - Maturities and Rate Sensitivity (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	$ 3,123,355	$ 3,098,220	$ 3,189,436
Fixed Rate	613,470
Floating Rate	2,509,885
Due in One Year or Less
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	688,643
Fixed Rate	96,805
Floating Rate	591,838
Due After One Year Through Five Years
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	1,728,908
Fixed Rate	408,214
Floating Rate	1,320,694
Due After Five Years
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	705,804
Fixed Rate	108,451
Floating Rate	597,353
Commercial & Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	1,144,332	1,053,925
Commercial & Industrial | Due in One Year or Less
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	407,566
Commercial & Industrial | Due After One Year Through Five Years
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	698,487
Commercial & Industrial | Due After Five Years
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	38,279
Owner occupied commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	407,317	394,210
Owner occupied commercial real estate | Due in One Year or Less
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	36,835
Owner occupied commercial real estate | Due After One Year Through Five Years
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	146,189
Owner occupied commercial real estate | Due After Five Years
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	224,293
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	1,109,237	1,143,751
Commercial real estate | Due in One Year or Less
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	140,769
Commercial real estate | Due After One Year Through Five Years
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	725,757
Commercial real estate | Due After Five Years
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	242,711
Construction, land & land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	201,992	249,704
Construction, land & land development | Due in One Year or Less
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	69,334
Construction, land & land development | Due After One Year Through Five Years
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	102,030
Construction, land & land development | Due After Five Years
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	30,628
Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	239,834	245,191
Residential mortgage | Due in One Year or Less
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	25,887
Residential mortgage | Due After One Year Through Five Years
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	53,390
Residential mortgage | Due After Five Years
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	160,557
Consumer and other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	20,643	$ 11,439
Consumer and other | Due in One Year or Less
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	8,252
Consumer and other | Due After One Year Through Five Years
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	3,055
Consumer and other | Due After Five Years
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for investment	$ 9,336