Loans - Age Analysis of Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual status, days past due	90 days
Financing Receivable, Recorded Investment, Aging [Abstract]
90 Days or More Past Due	$ 52	$ 16
Purchased Credit Impaired	46,174	14,154
Loans held for investment	3,130,669	1,799,155
Originated [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30-89 Past Due	13,994	10,006
90 Days or More Past Due	45	16
Total loans past due and still accruing	14,039	10,022
Nonaccrual	35,703	4,274
Current	1,883,815	1,546,435
Loans held for investment	1,933,557	1,560,731
Acquired [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30-89 Past Due	15,877	4,314
90 Days or More Past Due	7
Total loans past due and still accruing	15,884	4,314
Nonaccrual	3,302	570
Purchased Credit Impaired	46,174	14,154
Current	1,131,752	219,386
Loans held for investment	1,197,112	238,424
Commercial & Industrial [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Purchased Credit Impaired	13,905	2,432
Loans held for investment	1,206,452	788,410
Commercial & Industrial [Member] | Originated [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30-89 Past Due	2,064	7,266
90 Days or More Past Due	25
Total loans past due and still accruing	2,089	7,266
Nonaccrual	34,205	1,789
Current	813,754	750,755
Loans held for investment	850,048	759,810
Commercial & Industrial [Member] | Acquired [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30-89 Past Due	10,908	137
Total loans past due and still accruing	10,908	137
Nonaccrual	420
Purchased Credit Impaired	13,905	2,432
Current	331,171	26,031
Loans held for investment	356,404	28,600
Owner occupied commercial real estate [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Purchased Credit Impaired	7,149	1,248
Loans held for investment	353,889	163,592
Owner occupied commercial real estate [Member] | Originated [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30-89 Past Due	9,158	1,464
Total loans past due and still accruing	9,158	1,464
Nonaccrual	829	173
Current	178,921	146,560
Loans held for investment	188,908	148,197
Owner occupied commercial real estate [Member] | Acquired [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30-89 Past Due	741
Total loans past due and still accruing	741
Purchased Credit Impaired	7,149	1,248
Current	157,091	14,147
Loans held for investment	164,981	15,395
Commerical real estate [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Purchased Credit Impaired	12,288	7,261
Loans held for investment	904,115	339,006
Commerical real estate [Member] | Originated [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30-89 Past Due	1,108
Total loans past due and still accruing	1,108
Current	520,779	308,521
Loans held for investment	521,887	308,521
Commerical real estate [Member] | Acquired [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30-89 Past Due		1,141
Total loans past due and still accruing		1,141
Nonaccrual	1,590	570
Purchased Credit Impaired	12,288	7,261
Current	368,350	21,513
Loans held for investment	382,228	30,485
Construction, land & land development [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Purchased Credit Impaired	8,681	72
Loans held for investment	358,813	240,666
Construction, land & land development [Member] | Originated [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30-89 Past Due	181	677
Total loans past due and still accruing	181	677
Nonaccrual	472	940
Current	241,958	228,526
Loans held for investment	242,611	230,143
Construction, land & land development [Member] | Acquired [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30-89 Past Due	111	2,048
Total loans past due and still accruing	111	2,048
Purchased Credit Impaired	8,681	72
Current	107,410	8,403
Loans held for investment	116,202	10,523
Residential mortgage [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Purchased Credit Impaired	4,151	3,141
Loans held for investment	293,483	257,066
Residential mortgage [Member] | Originated [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30-89 Past Due	890	382
90 Days or More Past Due		16
Total loans past due and still accruing	890	398
Nonaccrual	197	1,277
Current	119,173	105,600
Loans held for investment	120,260	107,275
Residential mortgage [Member] | Acquired [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30-89 Past Due	4,065	981
90 Days or More Past Due	6
Total loans past due and still accruing	4,071	981
Nonaccrual	1,292
Purchased Credit Impaired	4,151	3,141
Current	163,709	145,669
Loans held for investment	173,223	149,791
Consumer and other [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans held for investment	13,917	10,415
Consumer and other [Member] | Originated [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30-89 Past Due	593	217
90 Days or More Past Due	20
Total loans past due and still accruing	613	217
Nonaccrual		95
Current	9,230	6,473
Loans held for investment	9,843	6,785
Consumer and other [Member] | Acquired [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30-89 Past Due	52	7
90 Days or More Past Due	1
Total loans past due and still accruing	53	7
Current	4,021	3,623
Loans held for investment	$ 4,074	$ 3,630