Loans and Allowance for Credit Losses - Age Analysis of Past Due Loans by Segment (Detail) - USD ($) $ in Thousands |
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Loans |
$ 5,407,376
|
$ 4,879,347
|
$ 4,683,750
|
Commercial Financial Agricultural And Other [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Loans |
1,163,383
|
1,139,547
|
|
Real Estate Construction [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Loans |
248,868
|
219,621
|
|
Residential real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Loans |
1,426,370
|
1,229,192
|
|
Commercial real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Loans |
2,019,096
|
1,742,210
|
|
Loans To Individuals [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Loans |
549,659
|
548,777
|
|
Commercial Financial Agricultural And Other [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Loans |
1,163,383
|
1,139,547
|
1,150,906
|
Real Estate Construction [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Loans |
248,868
|
219,621
|
220,736
|
Residential real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Loans |
1,426,370
|
1,229,192
|
1,224,465
|
Commercial real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Loans |
2,019,096
|
1,742,210
|
1,479,000
|
Loans To Individuals [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Loans |
549,659
|
548,777
|
$ 608,643
|
Originated Loans [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Total past due and nonaccrual |
41,362
|
40,497
|
|
Current |
4,965,999
|
4,737,974
|
|
Loans |
5,007,361
|
4,778,471
|
|
Originated Loans [Member] | Commercial Financial Agricultural And Other [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Total past due and nonaccrual |
19,220
|
20,554
|
|
Current |
1,103,521
|
1,110,594
|
|
Loans |
1,122,741
|
1,131,148
|
|
Originated Loans [Member] | Real Estate Construction [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Total past due and nonaccrual |
199
|
183
|
|
Current |
242,706
|
217,657
|
|
Loans |
242,905
|
217,840
|
|
Originated Loans [Member] | Residential real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Total past due and nonaccrual |
12,944
|
12,009
|
|
Current |
1,193,175
|
1,153,842
|
|
Loans |
1,206,119
|
1,165,851
|
|
Originated Loans [Member] | Commercial real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Total past due and nonaccrual |
5,472
|
4,092
|
|
Current |
1,886,713
|
1,712,951
|
|
Loans |
1,892,185
|
1,717,043
|
|
Originated Loans [Member] | Loans To Individuals [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Total past due and nonaccrual |
3,527
|
3,659
|
|
Current |
539,884
|
542,930
|
|
Loans |
543,411
|
546,589
|
|
Originated Loans [Member] | Commercial Financial Agricultural And Other [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Loans |
1,122,741
|
1,131,148
|
|
Originated Loans [Member] | Real Estate Construction [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Loans |
242,905
|
217,840
|
|
Originated Loans [Member] | Residential real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Loans |
1,206,119
|
1,165,851
|
|
Originated Loans [Member] | Commercial real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Loans |
1,892,185
|
1,717,043
|
|
Originated Loans [Member] | Loans To Individuals [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Loans |
543,411
|
546,589
|
|
Originated Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
9,292
|
8,601
|
|
Originated Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Financial Agricultural And Other [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
378
|
2,380
|
|
Originated Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Real Estate Construction [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
199
|
183
|
|
Originated Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Residential real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
4,618
|
4,133
|
|
Originated Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
2,198
|
265
|
|
Originated Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Loans To Individuals [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
1,899
|
1,640
|
|
Originated Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
1,883
|
2,363
|
|
Originated Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Financial Agricultural And Other [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
61
|
171
|
|
Originated Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Real Estate Construction [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
0
|
0
|
|
Originated Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Residential real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
1,025
|
1,089
|
|
Originated Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
28
|
327
|
|
Originated Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Loans To Individuals [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
769
|
776
|
|
Originated Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
1,745
|
2,097
|
|
Originated Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial Financial Agricultural And Other [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
40
|
75
|
|
Originated Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Real Estate Construction [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
0
|
0
|
|
Originated Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Residential real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
1,076
|
995
|
|
Originated Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
6
|
57
|
|
Originated Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Loans To Individuals [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
623
|
970
|
|
Originated Loans [Member] | Nonaccrual Commercial Loans [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
28,442
|
27,436
|
|
Originated Loans [Member] | Nonaccrual Commercial Loans [Member] | Commercial Financial Agricultural And Other [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
18,741
|
17,928
|
|
Originated Loans [Member] | Nonaccrual Commercial Loans [Member] | Real Estate Construction [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
0
|
0
|
|
Originated Loans [Member] | Nonaccrual Commercial Loans [Member] | Residential real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
6,225
|
5,792
|
|
Originated Loans [Member] | Nonaccrual Commercial Loans [Member] | Commercial real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
3,240
|
3,443
|
|
Originated Loans [Member] | Nonaccrual Commercial Loans [Member] | Loans To Individuals [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
236
|
273
|
|
Acquired Loans [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Total past due and nonaccrual |
2,570
|
1,302
|
|
Current |
397,445
|
99,574
|
|
Loans |
400,015
|
100,876
|
|
Acquired Loans [Member] | Commercial Financial Agricultural And Other [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Total past due and nonaccrual |
449
|
486
|
|
Current |
40,193
|
7,913
|
|
Loans |
40,642
|
8,399
|
|
Acquired Loans [Member] | Real Estate Construction [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Total past due and nonaccrual |
0
|
0
|
|
Current |
5,963
|
1,781
|
|
Loans |
5,963
|
1,781
|
|
Acquired Loans [Member] | Residential real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Total past due and nonaccrual |
945
|
643
|
|
Current |
219,306
|
62,698
|
|
Loans |
220,251
|
63,341
|
|
Acquired Loans [Member] | Commercial real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Total past due and nonaccrual |
1,077
|
162
|
|
Current |
125,834
|
25,005
|
|
Loans |
126,911
|
25,167
|
|
Acquired Loans [Member] | Loans To Individuals [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Total past due and nonaccrual |
99
|
11
|
|
Current |
6,149
|
2,177
|
|
Loans |
6,248
|
2,188
|
|
Acquired Loans [Member] | Commercial Financial Agricultural And Other [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Loans |
40,642
|
8,399
|
|
Acquired Loans [Member] | Real Estate Construction [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Loans |
5,963
|
1,781
|
|
Acquired Loans [Member] | Residential real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Loans |
220,251
|
63,341
|
|
Acquired Loans [Member] | Commercial real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Loans |
126,911
|
25,167
|
|
Acquired Loans [Member] | Loans To Individuals [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Loans |
6,248
|
2,188
|
|
Acquired Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
190
|
635
|
|
Acquired Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Financial Agricultural And Other [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
6
|
486
|
|
Acquired Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Real Estate Construction [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
0
|
0
|
|
Acquired Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Residential real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
148
|
148
|
|
Acquired Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
0
|
0
|
|
Acquired Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Loans To Individuals [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
36
|
1
|
|
Acquired Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
36
|
46
|
|
Acquired Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Financial Agricultural And Other [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
7
|
0
|
|
Acquired Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Real Estate Construction [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
0
|
0
|
|
Acquired Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Residential real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
9
|
39
|
|
Acquired Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
0
|
0
|
|
Acquired Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Loans To Individuals [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
20
|
7
|
|
Acquired Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
109
|
34
|
|
Acquired Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial Financial Agricultural And Other [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
0
|
0
|
|
Acquired Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Real Estate Construction [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
0
|
0
|
|
Acquired Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Residential real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
83
|
34
|
|
Acquired Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
0
|
0
|
|
Acquired Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Loans To Individuals [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
26
|
0
|
|
Acquired Loans [Member] | Nonaccrual Commercial Loans [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
2,235
|
587
|
|
Acquired Loans [Member] | Nonaccrual Commercial Loans [Member] | Commercial Financial Agricultural And Other [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
436
|
0
|
|
Acquired Loans [Member] | Nonaccrual Commercial Loans [Member] | Real Estate Construction [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
0
|
0
|
|
Acquired Loans [Member] | Nonaccrual Commercial Loans [Member] | Residential real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
705
|
422
|
|
Acquired Loans [Member] | Nonaccrual Commercial Loans [Member] | Commercial real estate [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
1,077
|
162
|
|
Acquired Loans [Member] | Nonaccrual Commercial Loans [Member] | Loans To Individuals [Member] |
|
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
Financing Receivable, Recorded Investment, Past Due |
$ 17
|
$ 3
|
|