Loans and Leases - Credit Quality Indicators (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	$ 3,452,581	$ 3,081,287
Total Loans and Leases Held for Investment, Acquired	413,588	538,780
Grade: 1. Cash secured/ 2. Fully secured [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	26,079	22,941
Total Loans and Leases Held for Investment, Acquired	0	1,120
Grade: 3. Strong [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	15,068	11,027
Total Loans and Leases Held for Investment, Acquired	0	0
Grade: 4. Satisfactory [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	43,101	57,507
Total Loans and Leases Held for Investment, Acquired	0	607
Grade: 5. Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	1,962,614	1,846,112
Total Loans and Leases Held for Investment, Acquired	234,413	306,841
Grade: 6. Pre-watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	634,674	491,740
Total Loans and Leases Held for Investment, Acquired	96,380	125,613
Grade: 7. Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	65,328	18,689
Total Loans and Leases Held for Investment, Acquired	5,259	18,035
Grade: 8. Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	32,148	42,809
Total Loans and Leases Held for Investment, Acquired	15,369	13,114
Grade: 9. Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	0	0
Total Loans and Leases Held for Investment, Acquired	0	0
Grade: 10. Loss [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	0	0
Total Loans and Leases Held for Investment, Acquired	0	0
Internally Assigned Grades [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	2,779,012	2,490,825
Total Loans and Leases Held for Investment, Acquired	351,421	465,330
Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	669,802	587,990
Total Loans and Leases Held for Investment, Acquired	59,976	72,705
Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	3,767	2,472
Total Loans and Leases Held for Investment, Acquired	2,191	745
Performing and Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	673,569	590,462
Total Loans and Leases Held for Investment, Acquired	62,167	73,450
Commercial, Financial and Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	867,636	833,100
Total Loans and Leases Held for Investment, Acquired	26,686	63,111
Commercial, Financial and Agricultural [Member] | Grade: 1. Cash secured/ 2. Fully secured [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	2,789	2,521
Total Loans and Leases Held for Investment, Acquired	0	1,120
Commercial, Financial and Agricultural [Member] | Grade: 3. Strong [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	14,369	9,206
Total Loans and Leases Held for Investment, Acquired	0	0
Commercial, Financial and Agricultural [Member] | Grade: 4. Satisfactory [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	18,511	30,283
Total Loans and Leases Held for Investment, Acquired	0	125
Commercial, Financial and Agricultural [Member] | Grade: 5. Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	575,671	593,205
Total Loans and Leases Held for Investment, Acquired	23,085	49,949
Commercial, Financial and Agricultural [Member] | Grade: 6. Pre-watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	222,325	179,990
Total Loans and Leases Held for Investment, Acquired	2,475	6,183
Commercial, Financial and Agricultural [Member] | Grade: 7. Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	26,323	4,027
Total Loans and Leases Held for Investment, Acquired	838	1,007
Commercial, Financial and Agricultural [Member] | Grade: 8. Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	7,648	13,868
Total Loans and Leases Held for Investment, Acquired	288	4,727
Commercial, Financial and Agricultural [Member] | Grade: 9. Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	0	0
Total Loans and Leases Held for Investment, Acquired	0	0
Commercial, Financial and Agricultural [Member] | Grade: 10. Loss [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	0	0
Total Loans and Leases Held for Investment, Acquired	0	0
Commercial, Financial and Agricultural [Member] | Internally Assigned Grades [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	867,636	833,100
Total Loans and Leases Held for Investment, Acquired	26,686	63,111
Real Estate-Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	1,442,681	1,235,681
Total Loans and Leases Held for Investment, Acquired	254,462	306,460
Real Estate-Commercial [Member] | Grade: 1. Cash secured/ 2. Fully secured [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	0	0
Total Loans and Leases Held for Investment, Acquired	0	0
Real Estate-Commercial [Member] | Grade: 3. Strong [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	699	1,821
Total Loans and Leases Held for Investment, Acquired	0	0
Real Estate-Commercial [Member] | Grade: 4. Satisfactory [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	24,325	26,950
Total Loans and Leases Held for Investment, Acquired	0	482
Real Estate-Commercial [Member] | Grade: 5. Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	1,072,909	960,258
Total Loans and Leases Held for Investment, Acquired	155,221	183,490
Real Estate-Commercial [Member] | Grade: 6. Pre-watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	287,933	209,844
Total Loans and Leases Held for Investment, Acquired	81,048	98,977
Real Estate-Commercial [Member] | Grade: 7. Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	35,402	12,974
Total Loans and Leases Held for Investment, Acquired	4,421	17,028
Real Estate-Commercial [Member] | Grade: 8. Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	21,413	23,834
Total Loans and Leases Held for Investment, Acquired	13,772	6,483
Real Estate-Commercial [Member] | Grade: 9. Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	0	0
Total Loans and Leases Held for Investment, Acquired	0	0
Real Estate-Commercial [Member] | Grade: 10. Loss [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	0	0
Total Loans and Leases Held for Investment, Acquired	0	0
Real Estate-Commercial [Member] | Internally Assigned Grades [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	1,442,681	1,235,681
Total Loans and Leases Held for Investment, Acquired	254,462	306,460
Real Estate-Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	188,895	171,244
Total Loans and Leases Held for Investment, Acquired	3,742	4,592
Real Estate-Construction [Member] | Grade: 1. Cash secured/ 2. Fully secured [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	23,290	20,420
Total Loans and Leases Held for Investment, Acquired	0	0
Real Estate-Construction [Member] | Grade: 3. Strong [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	0	0
Total Loans and Leases Held for Investment, Acquired	0	0
Real Estate-Construction [Member] | Grade: 4. Satisfactory [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	0	0
Total Loans and Leases Held for Investment, Acquired	0	0
Real Estate-Construction [Member] | Grade: 5. Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	77,773	76,899
Total Loans and Leases Held for Investment, Acquired	0	0
Real Estate-Construction [Member] | Grade: 6. Pre-watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	86,326	72,168
Total Loans and Leases Held for Investment, Acquired	3,742	4,592
Real Estate-Construction [Member] | Grade: 7. Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	1,400	1,392
Total Loans and Leases Held for Investment, Acquired	0	0
Real Estate-Construction [Member] | Grade: 8. Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	106	365
Total Loans and Leases Held for Investment, Acquired	0	0
Real Estate-Construction [Member] | Grade: 9. Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	0	0
Total Loans and Leases Held for Investment, Acquired	0	0
Real Estate-Construction [Member] | Grade: 10. Loss [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	0	0
Total Loans and Leases Held for Investment, Acquired	0	0
Real Estate-Construction [Member] | Internally Assigned Grades [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	188,895	171,244
Total Loans and Leases Held for Investment, Acquired	3,742	4,592
Real Estate-Residential Secured for Business Purpose [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	279,800	250,800
Total Loans and Leases Held for Investment, Acquired	66,531	91,167
Real Estate-Residential Secured for Business Purpose [Member] | Grade: 1. Cash secured/ 2. Fully secured [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	0	0
Total Loans and Leases Held for Investment, Acquired	0	0
Real Estate-Residential Secured for Business Purpose [Member] | Grade: 3. Strong [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	0	0
Total Loans and Leases Held for Investment, Acquired	0	0
Real Estate-Residential Secured for Business Purpose [Member] | Grade: 4. Satisfactory [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	265	274
Total Loans and Leases Held for Investment, Acquired	0	0
Real Estate-Residential Secured for Business Purpose [Member] | Grade: 5. Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	236,261	215,750
Total Loans and Leases Held for Investment, Acquired	56,107	73,402
Real Estate-Residential Secured for Business Purpose [Member] | Grade: 6. Pre-watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	38,090	29,738
Total Loans and Leases Held for Investment, Acquired	9,115	15,861
Real Estate-Residential Secured for Business Purpose [Member] | Grade: 7. Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	2,203	296
Total Loans and Leases Held for Investment, Acquired	0	0
Real Estate-Residential Secured for Business Purpose [Member] | Grade: 8. Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	2,981	4,742
Total Loans and Leases Held for Investment, Acquired	1,309	1,904
Real Estate-Residential Secured for Business Purpose [Member] | Grade: 9. Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	0	0
Total Loans and Leases Held for Investment, Acquired	0	0
Real Estate-Residential Secured for Business Purpose [Member] | Grade: 10. Loss [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	0	0
Total Loans and Leases Held for Investment, Acquired	0	0
Real Estate-Residential Secured for Business Purpose [Member] | Internally Assigned Grades [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	279,800	250,800
Total Loans and Leases Held for Investment, Acquired	66,531	91,167
Real Estate Residential Secured For Personal Purpose [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	327,833	260,654
Total Loans and Leases Held for Investment, Acquired	52,676	60,920
Real Estate Residential Secured For Personal Purpose [Member] | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	327,138	260,589
Total Loans and Leases Held for Investment, Acquired	51,556	60,477
Real Estate Residential Secured For Personal Purpose [Member] | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	695	65
Total Loans and Leases Held for Investment, Acquired	1,120	443
Real Estate Residential Secured For Personal Purpose [Member] | Performing and Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	327,833	260,654
Total Loans and Leases Held for Investment, Acquired	52,676	60,920
Real Estate-Home Equity Secured for Personal Purpose [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	177,632	171,884
Total Loans and Leases Held for Investment, Acquired	9,349	12,386
Real Estate-Home Equity Secured for Personal Purpose [Member] | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	177,115	171,527
Total Loans and Leases Held for Investment, Acquired	8,278	12,084
Real Estate-Home Equity Secured for Personal Purpose [Member] | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	517	357
Total Loans and Leases Held for Investment, Acquired	1,071	302
Real Estate-Home Equity Secured for Personal Purpose [Member] | Performing and Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	177,632	171,884
Total Loans and Leases Held for Investment, Acquired	9,349	12,386
Loans to Individuals [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	32,096	28,156
Total Loans and Leases Held for Investment, Acquired	142	144
Loans to Individuals [Member] | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	31,931	27,961
Total Loans and Leases Held for Investment, Acquired	142	144
Loans to Individuals [Member] | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	165	195
Total Loans and Leases Held for Investment, Acquired	0	0
Loans to Individuals [Member] | Performing and Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	32,096	28,156
Total Loans and Leases Held for Investment, Acquired	142	144
Lease Financings [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	136,008	129,768
Total Loans and Leases Held for Investment, Acquired	0	0
Lease Financings [Member] | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	133,618	127,913
Total Loans and Leases Held for Investment, Acquired	0	0
Lease Financings [Member] | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	2,390	1,855
Total Loans and Leases Held for Investment, Acquired	0	0
Lease Financings [Member] | Performing and Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans and Leases Held for Investment, Originated	136,008	129,768
Total Loans and Leases Held for Investment, Acquired	$ 0	$ 0