Loans and the Allowance for Credit Losses - Summary of Age Analysis of Loan Categories (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	$ 10,208,689	$ 9,733,478
90 Days or More Past Due and Accruing	9,560	7,804
Loans held for sale	17,560	25,277
Total loans, current	10,165,918	9,698,760
Total loans	10,226,249	9,758,755
Total Non-performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	35,293	39,488
Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	597,845	605,682
90 Days or More Past Due and Accruing	391	685
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	5,852,564	5,538,968
90 Days or More Past Due and Accruing	7,223	3,093
Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	1,907,875	1,721,378
90 Days or More Past Due and Accruing	1,175	2,840
Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	300,637	277,130
90 Days or More Past Due and Accruing	319	627
Commercial Real Estate - Land and Construction [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	919,416	833,880
90 Days or More Past Due and Accruing		51
Commercial Real Estate - Improved Property [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	4,933,148	4,705,088
90 Days or More Past Due and Accruing	7,223	3,042
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	1,549,768	1,590,320
90 Days or More Past Due and Accruing	452	559
Non-Accrual Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	31,714	35,742
TDRs Accruing Interest [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	3,579	3,746
Current [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	10,148,358	9,673,483
Loans held for sale, current	17,560	25,277
Current [Member] | Total Non-performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	15,910	14,449
Current [Member] | Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	592,060	599,189
Current [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	5,819,953	5,514,783
Current [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	1,896,553	1,702,587
Current [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	297,129	273,577
Current [Member] | Commercial Real Estate - Land and Construction [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	918,713	833,755
Current [Member] | Commercial Real Estate - Improved Property [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	4,901,240	4,681,028
Current [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	1,542,663	1,583,347
Current [Member] | Non-Accrual Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	12,751	11,174
Current [Member] | TDRs Accruing Interest [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	3,159	3,275
30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	17,955	14,755
30-59 Days Past Due [Member] | Total Non-performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	465	917
30-59 Days Past Due [Member] | Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	2,089	2,240
30-59 Days Past Due [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	9,052	6,377
30-59 Days Past Due [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	820	2,331
30-59 Days Past Due [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	2,420	1,532
30-59 Days Past Due [Member] | Commercial Real Estate - Land and Construction [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	703
30-59 Days Past Due [Member] | Commercial Real Estate - Improved Property [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	8,349	6,377
30-59 Days Past Due [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	3,574	2,275
30-59 Days Past Due [Member] | Non-Accrual Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	457	914
30-59 Days Past Due [Member] | TDRs Accruing Interest [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	8	3
60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	15,181	14,005
60-89 Days Past Due [Member] | Total Non-performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	1,283	691
60-89 Days Past Due [Member] | Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	547	602
60-89 Days Past Due [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	10,084	7,728
60-89 Days Past Due [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	3,169	3,254
60-89 Days Past Due [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	651	1,208
60-89 Days Past Due [Member] | Commercial Real Estate - Improved Property [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	10,084	7,728
60-89 Days Past Due [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	730	1,213
60-89 Days Past Due [Member] | Non-Accrual Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	1,113	564
60-89 Days Past Due [Member] | TDRs Accruing Interest [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	170	127
90 Days or More Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	27,195	31,235
90 Days or More Past Due [Member] | Total Non-performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	17,635	23,431
90 Days or More Past Due [Member] | Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	3,149	3,651
90 Days or More Past Due [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	13,475	10,080
90 Days or More Past Due [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	7,333	13,206
90 Days or More Past Due [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	437	813
90 Days or More Past Due [Member] | Commercial Real Estate - Land and Construction [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income		125
90 Days or More Past Due [Member] | Commercial Real Estate - Improved Property [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	13,475	9,955
90 Days or More Past Due [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	2,801	3,485
90 Days or More Past Due [Member] | Non-Accrual Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	17,393	23,090
90 Days or More Past Due [Member] | TDRs Accruing Interest [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	242	341
Total Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	60,331	59,995
Total Past Due [Member] | Total Non-performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	19,383	25,039
Total Past Due [Member] | Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	5,785	6,493
Total Past Due [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	32,611	24,185
Total Past Due [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	11,322	18,791
Total Past Due [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	3,508	3,553
Total Past Due [Member] | Commercial Real Estate - Land and Construction [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	703	125
Total Past Due [Member] | Commercial Real Estate - Improved Property [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	31,908	24,060
Total Past Due [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	7,105	6,973
Total Past Due [Member] | Non-Accrual Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	18,963	24,568
Total Past Due [Member] | TDRs Accruing Interest [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, net of unearned income	$ 420	$ 471