Loans and Leases - Reserve for Loan and Lease Losses and Recorded Investment in Loans and Leases (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014
Reserve for loan and lease losses:
Ending balance: individually evaluated for impairment	$ 410			$ 444
Ending balance: collectively evaluated for impairment	16,743			19,158
Total ending balance	17,153	$ 16,452	$ 17,628	19,602	$ 20,934	$ 20,662
Loans and leases held for investment:
Ending balance: individually evaluated for impairment	44,034			38,947
Ending balance: collectively evaluated for impairment	2,044,187			1,712,611
Acquired non-credit impaired loans	255,874			354,423
Acquired credit impaired loans	942			1,876
Total Loans and Leases Held for Investment	2,345,037		2,179,013	2,107,857
Commercial, Financial and Agricultural [Member]
Reserve for loan and lease losses:
Ending balance: individually evaluated for impairment	390			444
Ending balance: collectively evaluated for impairment	5,398			6,403
Total ending balance	5,788	5,630	6,418	6,847	6,712	6,920
Loans and leases held for investment:
Ending balance: individually evaluated for impairment	12,472			15,409
Ending balance: collectively evaluated for impairment	546,892			469,367
Acquired non-credit impaired loans	20,096			26,880
Acquired credit impaired loans	0			304
Total Loans and Leases Held for Investment	579,460		504,515	511,960
Real Estate-Commercial and Construction [Member]
Reserve for loan and lease losses:
Ending balance: individually evaluated for impairment	4			0
Ending balance: collectively evaluated for impairment	7,545			7,801
Total ending balance	7,549	6,471	6,572	7,801	9,648	8,943
Loans and leases held for investment:
Ending balance: individually evaluated for impairment	26,761			18,956
Ending balance: collectively evaluated for impairment	885,131			758,024
Acquired non-credit impaired loans	114,965			175,583
Acquired credit impaired loans	180			1,021
Total Loans and Leases Held for Investment	1,027,037			953,584
Real Estate-Residential Secured for Business Purpose [Member]
Reserve for loan and lease losses:
Ending balance: individually evaluated for impairment	16			0
Ending balance: collectively evaluated for impairment	40			616
Total ending balance	56	747	763	616	668	763
Loans and leases held for investment:
Ending balance: individually evaluated for impairment	3,772			3,633
Ending balance: collectively evaluated for impairment	118,601			48,290
Acquired non-credit impaired loans	107,087			135,480
Acquired credit impaired loans	762			491
Total Loans and Leases Held for Investment	230,222		218,783	187,894
Real Estate-Residential and Home Equity Secured for Personal Purpose [Member]
Reserve for loan and lease losses:
Ending balance: individually evaluated for impairment	0			0
Ending balance: collectively evaluated for impairment	1,301			1,188
Total ending balance	1,301	1,312	1,575	1,188	1,128	1,124
Loans and leases held for investment:
Ending balance: individually evaluated for impairment	1,029			949
Ending balance: collectively evaluated for impairment	333,887			288,263
Acquired non-credit impaired loans	13,420			16,135
Acquired credit impaired loans	0			60
Total Loans and Leases Held for Investment	348,336			305,407
Loans to Individuals [Member]
Reserve for loan and lease losses:
Ending balance: individually evaluated for impairment	0			0
Ending balance: collectively evaluated for impairment	411			389
Total ending balance	411	356	346	389	365	360
Loans and leases held for investment:
Ending balance: individually evaluated for impairment	0			0
Ending balance: collectively evaluated for impairment	30,880			28,070
Acquired non-credit impaired loans	306			345
Acquired credit impaired loans	0			0
Total Loans and Leases Held for Investment	31,186		29,732	28,415
Lease Financings [Member]
Reserve for loan and lease losses:
Ending balance: individually evaluated for impairment	0			0
Ending balance: collectively evaluated for impairment	1,121			1,125
Total ending balance	1,121	922	1,042	1,125	1,013	985
Loans and leases held for investment:
Ending balance: individually evaluated for impairment	0			0
Ending balance: collectively evaluated for impairment	128,796			120,597
Acquired non-credit impaired loans	0			0
Acquired credit impaired loans	0			0
Total Loans and Leases Held for Investment	128,796		125,440	120,597
Unallocated Financing Receivables [Member]
Reserve for loan and lease losses:
Ending balance: collectively evaluated for impairment	927			1,636
Total ending balance	$ 927	$ 1,014	$ 912	$ 1,636	$ 1,400	$ 1,567