Loans - Age Analysis of Loans (Details 6) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual status, days past due	90 days
Financing Receivable, Recorded Investment, Aging [Abstract]
30-89 Past Due	$ 4,290	$ 14,320
90 Days or More Past Due	4,233	16
Total loans past due and still accruing	8,523	14,336
Nonaccrual	24,385	4,844
Purchased Credit Impaired	9,405	14,154
Current	1,939,967	1,765,821
Loans held for investment	1,982,280	1,799,155	$ 1,504,998
Originated [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30-89 Past Due	4,226	10,006
90 Days or More Past Due	4,221	16
Total loans past due and still accruing	8,447	10,022
Nonaccrual	21,842	4,274
Current	1,779,346	1,546,435
Loans held for investment	1,809,635	1,560,731
Acquired [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30-89 Past Due	64	4,314
90 Days or More Past Due	12
Total loans past due and still accruing	76	4,314
Nonaccrual	2,543	570
Purchased Credit Impaired	9,405	14,154
Current	160,621	219,386
Loans held for investment	172,645	238,424
Commercial & Industrial [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Purchased Credit Impaired	900	2,432
Loans held for investment	820,337	788,410	725,583
Commercial & Industrial [Member] | Originated [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30-89 Past Due	1,330	7,266
Total loans past due and still accruing	1,330	7,266
Nonaccrual	20,304	1,789
Current	780,969	750,755
Loans held for investment	802,603	759,810
Commercial & Industrial [Member] | Acquired [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30-89 Past Due	10	137
Total loans past due and still accruing	10	137
Nonaccrual	427
Purchased Credit Impaired	900	2,432
Current	16,397	26,031
Loans held for investment	17,734	28,600
Owner occupied commercial real estate [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Purchased Credit Impaired	1,023	1,248
Loans held for investment	183,224	163,592	132,940
Owner occupied commercial real estate [Member] | Originated [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30-89 Past Due	2,215	1,464
Total loans past due and still accruing	2,215	1,464
Nonaccrual	854	173
Current	166,227	146,560
Loans held for investment	169,296	148,197
Owner occupied commercial real estate [Member] | Acquired [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Purchased Credit Impaired	1,023	1,248
Current	12,905	14,147
Loans held for investment	13,928	15,395
Commerical real estate [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Purchased Credit Impaired	4,474	7,261
Loans held for investment	483,628	339,006	308,700
Commerical real estate [Member] | Originated [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Current	465,989	308,521
Loans held for investment	465,989	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	1,640	570
Purchased Credit Impaired	4,474	7,261
Current	11,525	21,513
Loans held for investment	17,639	30,485
Construction, land & land development [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Purchased Credit Impaired	45	72
Loans held for investment	252,206	240,666	230,259
Construction, land & land development [Member] | Originated [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30-89 Past Due	567	677
90 Days or More Past Due	4,221
Total loans past due and still accruing	4,788	677
Nonaccrual	486	940
Current	241,954	228,526
Loans held for investment	247,228	230,143
Construction, land & land development [Member] | Acquired [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30-89 Past Due		2,048
Total loans past due and still accruing		2,048
Purchased Credit Impaired	45	72
Current	4,933	8,403
Loans held for investment	4,978	10,523
Residential mortgage [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Purchased Credit Impaired	2,963	3,141
Loans held for investment	230,796	257,066	100,818
Residential mortgage [Member] | Originated [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30-89 Past Due		382
90 Days or More Past Due		16
Total loans past due and still accruing		398
Nonaccrual	198	1,277
Current	114,535	105,600
Loans held for investment	114,733	107,275
Residential mortgage [Member] | Acquired [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30-89 Past Due	34	981
90 Days or More Past Due	9
Total loans past due and still accruing	43	981
Nonaccrual	476
Purchased Credit Impaired	2,963	3,141
Current	112,581	145,669
Loans held for investment	116,063	149,791
Consumer and other [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans held for investment	12,089	10,415	$ 6,698
Consumer and other [Member] | Originated [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30-89 Past Due	114	217
Total loans past due and still accruing	114	217
Nonaccrual		95
Current	9,672	6,473
Loans held for investment	9,786	6,785
Consumer and other [Member] | Acquired [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30-89 Past Due	20	7
90 Days or More Past Due	3
Total loans past due and still accruing	23	7
Current	2,280	3,623
Loans held for investment	$ 2,303	$ 3,630