Loans and Allowance for Credit Losses - Credit Risk Profile by Creditworthiness (Detail) - USD ($) $ in Thousands |
Dec. 31, 2019 |
Dec. 31, 2018 |
Originated Loans [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
$ 5,714,373
|
$ 5,275,296
|
Originated Loans [Member] | Pass [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
5,624,757
|
5,160,953
|
Originated Loans [Member] | Special Mention [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
43,393
|
79,294
|
Originated Loans [Member] | Substandard [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
46,223
|
35,049
|
Originated Loans [Member] | Doubtful [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
0
|
0
|
Originated Loans [Member] | Total Non-Pass [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
89,616
|
114,343
|
Originated Loans [Member] | Commercial, financial, agricultural and other [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
1,212,026
|
1,100,947
|
Originated Loans [Member] | Commercial, financial, agricultural and other [Member] | Pass [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
1,171,363
|
1,055,394
|
Originated Loans [Member] | Commercial, financial, agricultural and other [Member] | Special Mention [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
29,359
|
33,723
|
Originated Loans [Member] | Commercial, financial, agricultural and other [Member] | Substandard [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
11,304
|
11,830
|
Originated Loans [Member] | Commercial, financial, agricultural and other [Member] | Doubtful [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
0
|
0
|
Originated Loans [Member] | Commercial, financial, agricultural and other [Member] | Total Non-Pass [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
40,663
|
45,553
|
Originated Loans [Member] | Real Estate Construction [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
442,777
|
353,008
|
Originated Loans [Member] | Real Estate Construction [Member] | Pass [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
442,751
|
337,367
|
Originated Loans [Member] | Real Estate Construction [Member] | Special Mention [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
26
|
15,641
|
Originated Loans [Member] | Real Estate Construction [Member] | Substandard [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
0
|
0
|
Originated Loans [Member] | Real Estate Construction [Member] | Doubtful [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
0
|
0
|
Originated Loans [Member] | Real Estate Construction [Member] | Total Non-Pass [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
26
|
15,641
|
Originated Loans [Member] | Residential Real Estate [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
1,415,808
|
1,313,645
|
Originated Loans [Member] | Residential Real Estate [Member] | Pass [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
1,406,845
|
1,302,912
|
Originated Loans [Member] | Residential Real Estate [Member] | Special Mention [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
475
|
1,026
|
Originated Loans [Member] | Residential Real Estate [Member] | Substandard [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
8,488
|
9,707
|
Originated Loans [Member] | Residential Real Estate [Member] | Doubtful [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
0
|
0
|
Originated Loans [Member] | Residential Real Estate [Member] | Total Non-Pass [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
8,963
|
10,733
|
Originated Loans [Member] | Commercial real estate [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
1,958,346
|
1,922,349
|
Originated Loans [Member] | Commercial real estate [Member] | Pass [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
1,918,690
|
1,880,139
|
Originated Loans [Member] | Commercial real estate [Member] | Special Mention [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
13,533
|
28,904
|
Originated Loans [Member] | Commercial real estate [Member] | Substandard [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
26,123
|
13,306
|
Originated Loans [Member] | Commercial real estate [Member] | Doubtful [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
0
|
0
|
Originated Loans [Member] | Commercial real estate [Member] | Total Non-Pass [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
39,656
|
42,210
|
Originated Loans [Member] | Loans To Individuals [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
685,416
|
585,347
|
Originated Loans [Member] | Loans To Individuals [Member] | Pass [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
685,108
|
585,141
|
Originated Loans [Member] | Loans To Individuals [Member] | Special Mention [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
0
|
0
|
Originated Loans [Member] | Loans To Individuals [Member] | Substandard [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
308
|
206
|
Originated Loans [Member] | Loans To Individuals [Member] | Doubtful [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
0
|
0
|
Originated Loans [Member] | Loans To Individuals [Member] | Total Non-Pass [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
308
|
206
|
Acquired Loans [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
474,775
|
498,843
|
Acquired Loans [Member] | Pass [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
463,784
|
485,951
|
Acquired Loans [Member] | Special Mention [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
5,183
|
7,700
|
Acquired Loans [Member] | Substandard [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
5,808
|
5,192
|
Acquired Loans [Member] | Doubtful [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
0
|
0
|
Acquired Loans [Member] | Total Non-Pass [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
10,991
|
12,892
|
Acquired Loans [Member] | Commercial, financial, agricultural and other [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
29,827
|
37,526
|
Acquired Loans [Member] | Commercial, financial, agricultural and other [Member] | Pass [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
27,696
|
31,399
|
Acquired Loans [Member] | Commercial, financial, agricultural and other [Member] | Special Mention [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
2,009
|
5,890
|
Acquired Loans [Member] | Commercial, financial, agricultural and other [Member] | Substandard [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
122
|
237
|
Acquired Loans [Member] | Commercial, financial, agricultural and other [Member] | Doubtful [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
0
|
0
|
Acquired Loans [Member] | Commercial, financial, agricultural and other [Member] | Total Non-Pass [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
2,131
|
6,127
|
Acquired Loans [Member] | Real Estate Construction [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
6,262
|
5,970
|
Acquired Loans [Member] | Real Estate Construction [Member] | Pass [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
5,697
|
5,337
|
Acquired Loans [Member] | Real Estate Construction [Member] | Special Mention [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
565
|
633
|
Acquired Loans [Member] | Real Estate Construction [Member] | Substandard [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
0
|
0
|
Acquired Loans [Member] | Real Estate Construction [Member] | Doubtful [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
0
|
0
|
Acquired Loans [Member] | Real Estate Construction [Member] | Total Non-Pass [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
565
|
633
|
Acquired Loans [Member] | Residential Real Estate [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
265,554
|
248,760
|
Acquired Loans [Member] | Residential Real Estate [Member] | Pass [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
262,630
|
245,637
|
Acquired Loans [Member] | Residential Real Estate [Member] | Special Mention [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
537
|
736
|
Acquired Loans [Member] | Residential Real Estate [Member] | Substandard [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
2,387
|
2,387
|
Acquired Loans [Member] | Residential Real Estate [Member] | Doubtful [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
0
|
0
|
Acquired Loans [Member] | Residential Real Estate [Member] | Total Non-Pass [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
2,924
|
3,123
|
Acquired Loans [Member] | Commercial real estate [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
159,173
|
201,195
|
Acquired Loans [Member] | Commercial real estate [Member] | Pass [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
153,814
|
198,201
|
Acquired Loans [Member] | Commercial real estate [Member] | Special Mention [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
2,072
|
441
|
Acquired Loans [Member] | Commercial real estate [Member] | Substandard [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
3,287
|
2,553
|
Acquired Loans [Member] | Commercial real estate [Member] | Doubtful [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
0
|
0
|
Acquired Loans [Member] | Commercial real estate [Member] | Total Non-Pass [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
5,359
|
2,994
|
Acquired Loans [Member] | Loans To Individuals [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
13,959
|
5,392
|
Acquired Loans [Member] | Loans To Individuals [Member] | Pass [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
13,947
|
5,377
|
Acquired Loans [Member] | Loans To Individuals [Member] | Special Mention [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
0
|
0
|
Acquired Loans [Member] | Loans To Individuals [Member] | Substandard [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
12
|
15
|
Acquired Loans [Member] | Loans To Individuals [Member] | Doubtful [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
0
|
0
|
Acquired Loans [Member] | Loans To Individuals [Member] | Total Non-Pass [Member] |
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
Loans and Leases Receivable, Gross |
$ 12
|
$ 15
|