Loans, Changes in the Allowance for Loan Losses by Portfolio Segment (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Mar. 31, 2021	Dec. 31, 2020	Jan. 01, 2020
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Balance at beginning of period	$ 47,776	$ 21,907	$ 21,907
Off-Balance Sheet, Credit Loss, Liability	47,776	21,907	47,776	$ 50,776	$ 47,776
Provision for credit losses	3,000		7,000
Balance at end of period	50,776		47,776
Allowance for credit losses on loans
Provision for credit losses	(23,004)	53,001
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	383,702
Balance at end of period	352,938		383,702
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Total allowance for loan losses	383,702		383,702	352,938	383,702
Loans [Abstract]
Loans and Leases Receivable, Net of Deferred Income, Total				24,162,328	24,451,724
Cumulative Effect, Period Of Adoption, Adjusted Balance
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability						$ 40,597
First Staunton Bancshares [Member]
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Provision for credit losses			179
Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability						18,690
PPP
Loans [Abstract]
Loans and Leases Receivable, Net of Deferred Income, Total				836,566	767,757
Commercial and industrial
Loans [Abstract]
Loans and Leases Receivable, Net of Deferred Income, Total				7,664,501	7,701,422
Commercial real estate — owner occupied
Loans [Abstract]
Loans and Leases Receivable, Net of Deferred Income, Total				883,237	900,912
Commercial and business lending
Loans [Abstract]
Loans and Leases Receivable, Net of Deferred Income, Total				9,384,303	9,370,091
Commercial real estate — investor
Loans [Abstract]
Loans and Leases Receivable, Net of Deferred Income, Total				4,260,706	4,342,584
Real estate construction
Loans [Abstract]
Loans and Leases Receivable, Net of Deferred Income, Total				1,882,299	1,840,417
Commercial real estate lending
Loans [Abstract]
Loans and Leases Receivable, Net of Deferred Income, Total				6,143,004	6,183,001
Total commercial
Loans [Abstract]
Loans and Leases Receivable, Net of Deferred Income, Total				15,527,307	15,553,091
Home equity
Loans [Abstract]
Loans and Leases Receivable, Net of Deferred Income, Total				651,647	707,255
Total consumer
Loans [Abstract]
Loans and Leases Receivable, Net of Deferred Income, Total				8,635,020	8,898,632
Allowance for Loan Losses [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	383,702	201,371	201,371
Financing Receivable, Allowance for Credit Loss	352,938	201,371	201,371	352,938	383,702
Recoveries	8,410		11,422
Net Charge offs	(4,764)		(100,631)
Gross up of allowance for PCD loans at acquisition			3,504
Provision for credit losses	(26,000)		164,457
Balance at end of period	352,938		383,702
Allowance for credit losses on loans
Recoveries	8,410		11,422
Net Charge offs	(4,764)		(100,631)
Gross up of allowance for PCD loans at acquisition			3,504
Allowance for Loan and Lease Losses [Roll Forward]
Charge offs	(13,174)		(112,053)
Net Charge offs	(4,764)		(100,631)
Allowance for Loan Losses [Member] | Cumulative Effect, Period Of Adoption, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss						313,828
Allowance for Loan Losses [Member] | First Staunton Bancshares [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Provision for credit losses			2,543
Allowance for Loan Losses [Member] | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss						112,457
Allowance for Loan Losses [Member] | PPP
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	531	0	0
Financing Receivable, Allowance for Credit Loss	607	0	0	607	531
Recoveries	0		0
Net Charge offs	0		0
Gross up of allowance for PCD loans at acquisition			0
Provision for credit losses	76		531
Balance at end of period	607		531
Allowance for credit losses on loans
Recoveries	0		0
Net Charge offs	0		0
Gross up of allowance for PCD loans at acquisition			0
Allowance for Loan and Lease Losses [Roll Forward]
Charge offs	0		0
Net Charge offs	0		0
Allowance for Loan Losses [Member] | PPP | Cumulative Effect, Period Of Adoption, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss						0
Allowance for Loan Losses [Member] | PPP | First Staunton Bancshares [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Provision for credit losses			0
Allowance for Loan Losses [Member] | PPP | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss						0
Allowance for Loan Losses [Member] | Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	142,793	91,133	91,133
Financing Receivable, Allowance for Credit Loss	142,793	91,133	142,793	124,707	142,793
Recoveries	4,490		7,004
Net Charge offs	1,367		(73,316)
Gross up of allowance for PCD loans at acquisition			293
Provision for credit losses	(19,453)		71,355
Balance at end of period	124,707		142,793
Allowance for credit losses on loans
Recoveries	4,490		7,004
Net Charge offs	1,367		(73,316)
Gross up of allowance for PCD loans at acquisition			293
Allowance for Loan and Lease Losses [Roll Forward]
Charge offs	(3,123)		(80,320)
Net Charge offs	1,367		(73,316)
Allowance for Loan Losses [Member] | Commercial and industrial | Cumulative Effect, Period Of Adoption, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss						144,052
Allowance for Loan Losses [Member] | Commercial and industrial | First Staunton Bancshares [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Provision for credit losses			408
Allowance for Loan Losses [Member] | Commercial and industrial | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss						52,919
Allowance for Loan Losses [Member] | Commercial real estate — owner occupied
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	11,274	10,284	10,284
Financing Receivable, Allowance for Credit Loss	11,274	10,284	11,274	11,786	11,274
Recoveries	4		147
Net Charge offs	4		(272)
Gross up of allowance for PCD loans at acquisition			890
Provision for credit losses	508		1,967
Balance at end of period	11,786		11,274
Allowance for credit losses on loans
Recoveries	4		147
Net Charge offs	4		(272)
Gross up of allowance for PCD loans at acquisition			890
Allowance for Loan and Lease Losses [Roll Forward]
Charge offs	0		(419)
Net Charge offs	4		(272)
Allowance for Loan Losses [Member] | Commercial real estate — owner occupied | Cumulative Effect, Period Of Adoption, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss						8,433
Allowance for Loan Losses [Member] | Commercial real estate — owner occupied | First Staunton Bancshares [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Provision for credit losses			255
Allowance for Loan Losses [Member] | Commercial real estate — owner occupied | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss						(1,851)
Allowance for Loan Losses [Member] | Commercial and business lending
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	154,598	101,417	101,417
Financing Receivable, Allowance for Credit Loss	137,099	101,417	101,417	137,099	154,598
Recoveries	4,494		7,151
Net Charge offs	1,370		(73,588)
Gross up of allowance for PCD loans at acquisition			1,183
Provision for credit losses	(18,869)		73,853
Balance at end of period	137,099		154,598
Allowance for credit losses on loans
Recoveries	4,494		7,151
Net Charge offs	1,370		(73,588)
Gross up of allowance for PCD loans at acquisition			1,183
Allowance for Loan and Lease Losses [Roll Forward]
Charge offs	(3,123)		(80,739)
Net Charge offs	1,370		(73,588)
Allowance for Loan Losses [Member] | Commercial and business lending | Cumulative Effect, Period Of Adoption, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss						152,485
Allowance for Loan Losses [Member] | Commercial and business lending | First Staunton Bancshares [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Provision for credit losses			663
Allowance for Loan Losses [Member] | Commercial and business lending | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss						51,068
Allowance for Loan Losses [Member] | Commercial real estate — investor
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	93,435	40,514	40,514
Financing Receivable, Allowance for Credit Loss	93,435	40,514	93,435	89,243	93,435
Recoveries	2,854		643
Net Charge offs	(5,886)		(22,277)
Gross up of allowance for PCD loans at acquisition			753
Provision for credit losses	1,694		71,933
Balance at end of period	89,243		93,435
Allowance for credit losses on loans
Recoveries	2,854		643
Net Charge offs	(5,886)		(22,277)
Gross up of allowance for PCD loans at acquisition			753
Allowance for Loan and Lease Losses [Roll Forward]
Charge offs	(8,739)		(22,920)
Net Charge offs	(5,886)		(22,277)
Allowance for Loan Losses [Member] | Commercial real estate — investor | Cumulative Effect, Period Of Adoption, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss						42,555
Allowance for Loan Losses [Member] | Commercial real estate — investor | First Staunton Bancshares [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Provision for credit losses			472
Allowance for Loan Losses [Member] | Commercial real estate — investor | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss						2,041
Allowance for Loan Losses [Member] | Real estate construction
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	59,193	24,915	24,915
Financing Receivable, Allowance for Credit Loss	54,243	24,915	24,915	54,243	59,193
Recoveries	31		49
Net Charge offs	29		31
Gross up of allowance for PCD loans at acquisition			435
Provision for credit losses	(4,979)		25,854
Balance at end of period	54,243		59,193
Allowance for credit losses on loans
Recoveries	31		49
Net Charge offs	29		31
Gross up of allowance for PCD loans at acquisition			435
Allowance for Loan and Lease Losses [Roll Forward]
Charge offs	(3)		(19)
Net Charge offs	29		31
Allowance for Loan Losses [Member] | Real estate construction | Cumulative Effect, Period Of Adoption, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss						32,382
Allowance for Loan Losses [Member] | Real estate construction | First Staunton Bancshares [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Provision for credit losses			492
Allowance for Loan Losses [Member] | Real estate construction | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss						7,467
Allowance for Loan Losses [Member] | Commercial real estate lending
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	152,629	65,428	65,428
Financing Receivable, Allowance for Credit Loss	152,629	65,428	152,629	143,486	152,629
Recoveries	2,885		692
Net Charge offs	(5,857)		(22,246)
Gross up of allowance for PCD loans at acquisition			1,188
Provision for credit losses	(3,286)		97,787
Balance at end of period	143,486		152,629
Allowance for credit losses on loans
Recoveries	2,885		692
Net Charge offs	(5,857)		(22,246)
Gross up of allowance for PCD loans at acquisition			1,188
Allowance for Loan and Lease Losses [Roll Forward]
Charge offs	(8,742)		(22,938)
Net Charge offs	(5,857)		(22,246)
Allowance for Loan Losses [Member] | Commercial real estate lending | Cumulative Effect, Period Of Adoption, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss						74,937
Allowance for Loan Losses [Member] | Commercial real estate lending | First Staunton Bancshares [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Provision for credit losses			964
Allowance for Loan Losses [Member] | Commercial real estate lending | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss						9,508
Allowance for Loan Losses [Member] | Total commercial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	307,226	166,846	166,846
Financing Receivable, Allowance for Credit Loss	280,585	166,846	166,846	280,585	307,226
Recoveries	7,379		7,844
Net Charge offs	(4,487)		(95,834)
Gross up of allowance for PCD loans at acquisition			2,371
Provision for credit losses	(22,155)		171,641
Balance at end of period	280,585		307,226
Allowance for credit losses on loans
Recoveries	7,379		7,844
Net Charge offs	(4,487)		(95,834)
Gross up of allowance for PCD loans at acquisition			2,371
Allowance for Loan and Lease Losses [Roll Forward]
Charge offs	(11,865)		(103,677)
Net Charge offs	(4,487)		(95,834)
Allowance for Loan Losses [Member] | Total commercial | Cumulative Effect, Period Of Adoption, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss						227,422
Allowance for Loan Losses [Member] | Total commercial | First Staunton Bancshares [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Provision for credit losses			1,627
Allowance for Loan Losses [Member] | Total commercial | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss						60,576
Allowance for Loan Losses [Member] | Residential mortgage
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	42,996	16,960	16,960
Financing Receivable, Allowance for Credit Loss	45,215	16,960	16,960	45,215	42,996
Recoveries	134		500
Net Charge offs	(109)		(1,367)
Gross up of allowance for PCD loans at acquisition			651
Provision for credit losses	2,328		(6,864)
Balance at end of period	45,215		42,996
Allowance for credit losses on loans
Recoveries	134		500
Net Charge offs	(109)		(1,367)
Gross up of allowance for PCD loans at acquisition			651
Allowance for Loan and Lease Losses [Roll Forward]
Charge offs	(243)		(1,867)
Net Charge offs	(109)		(1,367)
Allowance for Loan Losses [Member] | Residential mortgage | Cumulative Effect, Period Of Adoption, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss						50,175
Allowance for Loan Losses [Member] | Residential mortgage | First Staunton Bancshares [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Provision for credit losses			403
Allowance for Loan Losses [Member] | Residential mortgage | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss						33,215
Allowance for Loan Losses [Member] | Home equity
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	18,849	10,926	10,926
Financing Receivable, Allowance for Credit Loss	16,371	10,926	10,926	16,371	18,849
Recoveries	583		1,978
Net Charge offs	344		259
Gross up of allowance for PCD loans at acquisition			422
Provision for credit losses	(2,822)		(4,781)
Balance at end of period	16,371		18,849
Allowance for credit losses on loans
Recoveries	583		1,978
Net Charge offs	344		259
Gross up of allowance for PCD loans at acquisition			422
Allowance for Loan and Lease Losses [Roll Forward]
Charge offs	(238)		(1,719)
Net Charge offs	344		259
Allowance for Loan Losses [Member] | Home equity | Cumulative Effect, Period Of Adoption, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss						22,575
Allowance for Loan Losses [Member] | Home equity | First Staunton Bancshares [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Provision for credit losses			374
Allowance for Loan Losses [Member] | Home equity | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss						11,649
Allowance for Loan Losses [Member] | Other consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	14,630	6,639	6,639
Financing Receivable, Allowance for Credit Loss	14,630	6,639	14,630	10,767	14,630
Recoveries	315		1,101
Net Charge offs	(511)		(3,689)
Gross up of allowance for PCD loans at acquisition			61
Provision for credit losses	(3,351)		4,462
Balance at end of period	10,767		14,630
Allowance for credit losses on loans
Recoveries	315		1,101
Net Charge offs	(511)		(3,689)
Gross up of allowance for PCD loans at acquisition			61
Allowance for Loan and Lease Losses [Roll Forward]
Charge offs	(827)		(4,790)
Net Charge offs	(511)		(3,689)
Allowance for Loan Losses [Member] | Other consumer | Cumulative Effect, Period Of Adoption, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss						13,655
Allowance for Loan Losses [Member] | Other consumer | First Staunton Bancshares [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Provision for credit losses			140
Allowance for Loan Losses [Member] | Other consumer | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss						7,016
Allowance for Loan Losses [Member] | Total consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	76,475	34,525	34,525
Financing Receivable, Allowance for Credit Loss	76,475	34,525	76,475	72,353	76,475
Recoveries	1,031		3,579
Net Charge offs	(277)		(4,797)
Gross up of allowance for PCD loans at acquisition			1,134
Provision for credit losses	(3,845)		(7,183)
Balance at end of period	72,353		76,475
Allowance for credit losses on loans
Recoveries	1,031		3,579
Net Charge offs	(277)		(4,797)
Gross up of allowance for PCD loans at acquisition			1,134
Allowance for Loan and Lease Losses [Roll Forward]
Charge offs	(1,308)		(8,376)
Net Charge offs	(277)		(4,797)
Allowance for Loan Losses [Member] | Total consumer | Cumulative Effect, Period Of Adoption, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss						86,405
Allowance for Loan Losses [Member] | Total consumer | First Staunton Bancshares [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Provision for credit losses			917
Allowance for Loan Losses [Member] | Total consumer | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss						51,880
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member]
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Balance at beginning of period	47,776	21,907	21,907
Off-Balance Sheet, Credit Loss, Liability	47,776	21,907	47,776	50,776	47,776
Provision for credit losses	3,000		7,000
Balance at end of period	50,776		47,776
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Cumulative Effect, Period Of Adoption, Adjusted Balance
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability						40,597
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | First Staunton Bancshares [Member]
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Provision for credit losses			179
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability						18,690
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Commercial and industrial
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Balance at beginning of period	22,311	12,276	12,276
Off-Balance Sheet, Credit Loss, Liability	22,311	12,276	22,311	24,728	22,311
Provision for credit losses	2,417		13,972
Balance at end of period	24,728		22,311
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Commercial and industrial | Cumulative Effect, Period Of Adoption, Adjusted Balance
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability						8,278
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Commercial and industrial | First Staunton Bancshares [Member]
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Provision for credit losses			61
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Commercial and industrial | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability						(3,998)
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Commercial real estate — owner occupied
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Balance at beginning of period	266	127	127
Off-Balance Sheet, Credit Loss, Liability	304	127	127	304	266
Provision for credit losses	38		135
Balance at end of period	304		266
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Commercial real estate — owner occupied | Cumulative Effect, Period Of Adoption, Adjusted Balance
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability						127
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Commercial real estate — owner occupied | First Staunton Bancshares [Member]
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Provision for credit losses			4
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Commercial real estate — owner occupied | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability						0
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Commercial and business lending
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Balance at beginning of period	22,577	12,403	12,403
Off-Balance Sheet, Credit Loss, Liability	22,577	12,403	22,577	25,033	22,577
Provision for credit losses	2,455		14,108
Balance at end of period	25,033		22,577
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Commercial and business lending | Cumulative Effect, Period Of Adoption, Adjusted Balance
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability						8,405
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Commercial and business lending | First Staunton Bancshares [Member]
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Provision for credit losses			65
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Commercial and business lending | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability						(3,998)
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Commercial real estate — investor
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Balance at beginning of period	636	530	530
Off-Balance Sheet, Credit Loss, Liability	636	530	636	651	636
Provision for credit losses	15		(141)
Balance at end of period	651		636
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Commercial real estate — investor | Cumulative Effect, Period Of Adoption, Adjusted Balance
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability						776
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Commercial real estate — investor | First Staunton Bancshares [Member]
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Provision for credit losses			2
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Commercial real estate — investor | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability						246
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Real estate construction
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Balance at beginning of period	18,887	7,532	7,532
Off-Balance Sheet, Credit Loss, Liability	18,887	7,532	18,887	19,309	18,887
Provision for credit losses	422		(7,038)
Balance at end of period	19,309		18,887
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Real estate construction | Cumulative Effect, Period Of Adoption, Adjusted Balance
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability						25,879
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Real estate construction | First Staunton Bancshares [Member]
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Provision for credit losses			45
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Real estate construction | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability						18,347
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Commercial real estate lending
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Balance at beginning of period	19,523	8,062	8,062
Off-Balance Sheet, Credit Loss, Liability	19,960	8,062	8,062	19,960	19,523
Provision for credit losses	437		(7,179)
Balance at end of period	19,960		19,523
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Commercial real estate lending | Cumulative Effect, Period Of Adoption, Adjusted Balance
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability						26,655
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Commercial real estate lending | First Staunton Bancshares [Member]
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Provision for credit losses			47
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Commercial real estate lending | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability						18,593
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Total commercial
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Balance at beginning of period	42,101	20,465	20,465
Off-Balance Sheet, Credit Loss, Liability	42,101	20,465	42,101	44,993	42,101
Provision for credit losses	2,892		6,929
Balance at end of period	44,993		42,101
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Total commercial | Cumulative Effect, Period Of Adoption, Adjusted Balance
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability						35,060
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Total commercial | First Staunton Bancshares [Member]
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Provision for credit losses			112
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Total commercial | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability						14,595
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Home equity
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Balance at beginning of period	3,118	1,038	1,038
Off-Balance Sheet, Credit Loss, Liability	2,919	1,038	1,038	2,919	3,118
Provision for credit losses	(199)		(577)
Balance at end of period	2,919		3,118
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Home equity | Cumulative Effect, Period Of Adoption, Adjusted Balance
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability						3,629
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Home equity | First Staunton Bancshares [Member]
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Provision for credit losses			66
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Home equity | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability						2,591
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Other consumer
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Balance at beginning of period	2,557	405	405
Off-Balance Sheet, Credit Loss, Liability	2,557	405	2,557	2,865	2,557
Provision for credit losses	307		649
Balance at end of period	2,865		2,557
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Other consumer | Cumulative Effect, Period Of Adoption, Adjusted Balance
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability						1,909
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Other consumer | First Staunton Bancshares [Member]
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Provision for credit losses			0
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Other consumer | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability						1,504
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Total consumer
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Balance at beginning of period	5,675	1,443	1,443
Off-Balance Sheet, Credit Loss, Liability	5,675	1,443	5,675	5,783	5,675
Provision for credit losses	108		72
Balance at end of period	5,783		5,675
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Total consumer | Cumulative Effect, Period Of Adoption, Adjusted Balance
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability						5,538
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Total consumer | First Staunton Bancshares [Member]
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Provision for credit losses			66
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Total consumer | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability						4,095
Allowance for Loans Losses and Unfunded Commitments [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Recoveries	8,410		11,422
Net Charge offs	(4,764)		(100,631)
Gross up of allowance for PCD loans at acquisition			3,504
Allowance for credit losses on loans
Balance at beginning of period	431,478	223,278	223,278
Allowance for Credit Losses on Loans	431,478	223,278	431,478	$ 403,714	$ 431,478
Recoveries	8,410		11,422
Net Charge offs	(4,764)		(100,631)
Gross up of allowance for PCD loans at acquisition			3,504
Provision for credit losses	(23,000)		171,457
Balance at end of period	403,714		431,478
Percent of Loans				1.67%	1.76%
Allowance for Loan and Lease Losses [Roll Forward]
Charge offs	(13,174)		(112,053)
Net Charge offs	(4,764)		(100,631)
Allowance for Loans Losses and Unfunded Commitments [Member] | Cumulative Effect, Period Of Adoption, Adjusted Balance
Allowance for credit losses on loans
Allowance for Credit Losses on Loans						354,425
Allowance for Loans Losses and Unfunded Commitments [Member] | First Staunton Bancshares [Member]
Allowance for credit losses on loans
Provision for credit losses			2,722
Allowance for Loans Losses and Unfunded Commitments [Member] | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Allowance for credit losses on loans
Allowance for Credit Losses on Loans						131,147
Allowance for Loans Losses and Unfunded Commitments [Member] | PPP
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Recoveries	0		0
Net Charge offs	0		0
Gross up of allowance for PCD loans at acquisition			0
Allowance for credit losses on loans
Balance at beginning of period	531	0	0
Allowance for Credit Losses on Loans	607	0	0	$ 607	$ 531
Recoveries	0		0
Net Charge offs	0		0
Gross up of allowance for PCD loans at acquisition			0
Provision for credit losses	76		531
Balance at end of period	607		531
Percent of Loans				0.07%	0.07%
Allowance for Loan and Lease Losses [Roll Forward]
Charge offs	0		0
Net Charge offs	0		0
Allowance for Loans Losses and Unfunded Commitments [Member] | PPP | Cumulative Effect, Period Of Adoption, Adjusted Balance
Allowance for credit losses on loans
Allowance for Credit Losses on Loans						0
Allowance for Loans Losses and Unfunded Commitments [Member] | PPP | First Staunton Bancshares [Member]
Allowance for credit losses on loans
Provision for credit losses			0
Allowance for Loans Losses and Unfunded Commitments [Member] | PPP | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Allowance for credit losses on loans
Allowance for Credit Losses on Loans						0
Allowance for Loans Losses and Unfunded Commitments [Member] | Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Recoveries	4,490		7,004
Net Charge offs	1,367		(73,316)
Gross up of allowance for PCD loans at acquisition			293
Allowance for credit losses on loans
Balance at beginning of period	165,105	103,409	103,409
Allowance for Credit Losses on Loans	165,105	103,409	165,105	$ 149,435	$ 165,105
Recoveries	4,490		7,004
Net Charge offs	1,367		(73,316)
Gross up of allowance for PCD loans at acquisition			293
Provision for credit losses	(17,037)		85,327
Balance at end of period	149,435		165,105
Percent of Loans				1.95%	2.14%
Allowance for Loan and Lease Losses [Roll Forward]
Charge offs	(3,123)		(80,320)
Net Charge offs	1,367		(73,316)
Allowance for Loans Losses and Unfunded Commitments [Member] | Commercial and industrial | Cumulative Effect, Period Of Adoption, Adjusted Balance
Allowance for credit losses on loans
Allowance for Credit Losses on Loans						152,330
Allowance for Loans Losses and Unfunded Commitments [Member] | Commercial and industrial | First Staunton Bancshares [Member]
Allowance for credit losses on loans
Provision for credit losses			469
Allowance for Loans Losses and Unfunded Commitments [Member] | Commercial and industrial | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Allowance for credit losses on loans
Allowance for Credit Losses on Loans						48,921
Allowance for Loans Losses and Unfunded Commitments [Member] | Commercial real estate — owner occupied
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Recoveries	4		147
Net Charge offs	4		(272)
Gross up of allowance for PCD loans at acquisition			890
Allowance for credit losses on loans
Balance at beginning of period	11,539	10,411	10,411
Allowance for Credit Losses on Loans	11,539	10,411	11,539	$ 12,090	$ 11,539
Recoveries	4		147
Net Charge offs	4		(272)
Gross up of allowance for PCD loans at acquisition			890
Provision for credit losses	547		2,102
Balance at end of period	12,090		11,539
Percent of Loans				1.37%	1.28%
Allowance for Loan and Lease Losses [Roll Forward]
Charge offs	0		(419)
Net Charge offs	4		(272)
Allowance for Loans Losses and Unfunded Commitments [Member] | Commercial real estate — owner occupied | Cumulative Effect, Period Of Adoption, Adjusted Balance
Allowance for credit losses on loans
Allowance for Credit Losses on Loans						8,560
Allowance for Loans Losses and Unfunded Commitments [Member] | Commercial real estate — owner occupied | First Staunton Bancshares [Member]
Allowance for credit losses on loans
Provision for credit losses			259
Allowance for Loans Losses and Unfunded Commitments [Member] | Commercial real estate — owner occupied | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Allowance for credit losses on loans
Allowance for Credit Losses on Loans						(1,851)
Allowance for Loans Losses and Unfunded Commitments [Member] | Commercial and business lending
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Recoveries	4,494		7,151
Net Charge offs	1,370		(73,588)
Gross up of allowance for PCD loans at acquisition			1,183
Allowance for credit losses on loans
Balance at beginning of period	177,175	113,820	113,820
Allowance for Credit Losses on Loans	162,132	113,820	113,820	$ 162,132	$ 177,175
Recoveries	4,494		7,151
Net Charge offs	1,370		(73,588)
Gross up of allowance for PCD loans at acquisition			1,183
Provision for credit losses	(16,414)		87,961
Balance at end of period	162,132		177,175
Percent of Loans				1.73%	1.89%
Allowance for Loan and Lease Losses [Roll Forward]
Charge offs	(3,123)		(80,739)
Net Charge offs	1,370		(73,588)
Allowance for Loans Losses and Unfunded Commitments [Member] | Commercial and business lending | Cumulative Effect, Period Of Adoption, Adjusted Balance
Allowance for credit losses on loans
Allowance for Credit Losses on Loans						160,890
Allowance for Loans Losses and Unfunded Commitments [Member] | Commercial and business lending | First Staunton Bancshares [Member]
Allowance for credit losses on loans
Provision for credit losses			728
Allowance for Loans Losses and Unfunded Commitments [Member] | Commercial and business lending | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Allowance for credit losses on loans
Allowance for Credit Losses on Loans						47,070
Allowance for Loans Losses and Unfunded Commitments [Member] | Commercial real estate — investor
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Recoveries	2,854		643
Net Charge offs	(5,886)		(22,277)
Gross up of allowance for PCD loans at acquisition			753
Allowance for credit losses on loans
Balance at beginning of period	94,071	41,044	41,044
Allowance for Credit Losses on Loans	94,071	41,044	94,071	$ 89,894	$ 94,071
Recoveries	2,854		643
Net Charge offs	(5,886)		(22,277)
Gross up of allowance for PCD loans at acquisition			753
Provision for credit losses	1,709		71,792
Balance at end of period	89,894		94,071
Percent of Loans				2.11%	2.17%
Allowance for Loan and Lease Losses [Roll Forward]
Charge offs	(8,739)		(22,920)
Net Charge offs	(5,886)		(22,277)
Allowance for Loans Losses and Unfunded Commitments [Member] | Commercial real estate — investor | Cumulative Effect, Period Of Adoption, Adjusted Balance
Allowance for credit losses on loans
Allowance for Credit Losses on Loans						43,331
Allowance for Loans Losses and Unfunded Commitments [Member] | Commercial real estate — investor | First Staunton Bancshares [Member]
Allowance for credit losses on loans
Provision for credit losses			474
Allowance for Loans Losses and Unfunded Commitments [Member] | Commercial real estate — investor | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Allowance for credit losses on loans
Allowance for Credit Losses on Loans						2,287
Allowance for Loans Losses and Unfunded Commitments [Member] | Real estate construction
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Recoveries	31		49
Net Charge offs	29		31
Gross up of allowance for PCD loans at acquisition			435
Allowance for credit losses on loans
Balance at beginning of period	78,080	32,447	32,447
Allowance for Credit Losses on Loans	73,552	32,447	32,447	$ 73,552	$ 78,080
Recoveries	31		49
Net Charge offs	29		31
Gross up of allowance for PCD loans at acquisition			435
Provision for credit losses	(4,557)		18,816
Balance at end of period	73,552		78,080
Percent of Loans				3.91%	4.24%
Allowance for Loan and Lease Losses [Roll Forward]
Charge offs	(3)		(19)
Net Charge offs	29		31
Allowance for Loans Losses and Unfunded Commitments [Member] | Real estate construction | Cumulative Effect, Period Of Adoption, Adjusted Balance
Allowance for credit losses on loans
Allowance for Credit Losses on Loans						58,261
Allowance for Loans Losses and Unfunded Commitments [Member] | Real estate construction | First Staunton Bancshares [Member]
Allowance for credit losses on loans
Provision for credit losses			537
Allowance for Loans Losses and Unfunded Commitments [Member] | Real estate construction | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Allowance for credit losses on loans
Allowance for Credit Losses on Loans						25,814
Allowance for Loans Losses and Unfunded Commitments [Member] | Commercial real estate lending
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Recoveries	2,885		692
Net Charge offs	(5,857)		(22,246)
Gross up of allowance for PCD loans at acquisition			1,188
Allowance for credit losses on loans
Balance at beginning of period	172,152	73,490	73,490
Allowance for Credit Losses on Loans	163,446	73,490	73,490	$ 163,446	$ 172,152
Recoveries	2,885		692
Net Charge offs	(5,857)		(22,246)
Gross up of allowance for PCD loans at acquisition			1,188
Provision for credit losses	(2,849)		90,608
Balance at end of period	163,446		172,152
Percent of Loans				2.66%	2.78%
Allowance for Loan and Lease Losses [Roll Forward]
Charge offs	(8,742)		(22,938)
Net Charge offs	(5,857)		(22,246)
Allowance for Loans Losses and Unfunded Commitments [Member] | Commercial real estate lending | Cumulative Effect, Period Of Adoption, Adjusted Balance
Allowance for credit losses on loans
Allowance for Credit Losses on Loans						101,591
Allowance for Loans Losses and Unfunded Commitments [Member] | Commercial real estate lending | First Staunton Bancshares [Member]
Allowance for credit losses on loans
Provision for credit losses			1,011
Allowance for Loans Losses and Unfunded Commitments [Member] | Commercial real estate lending | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Allowance for credit losses on loans
Allowance for Credit Losses on Loans						28,101
Allowance for Loans Losses and Unfunded Commitments [Member] | Total commercial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Recoveries	7,379		7,844
Net Charge offs	(4,487)		(95,834)
Gross up of allowance for PCD loans at acquisition			2,371
Allowance for credit losses on loans
Balance at beginning of period	349,327	187,311	187,311
Allowance for Credit Losses on Loans	349,327	187,311	349,327	$ 325,578	$ 349,327
Recoveries	7,379		7,844
Net Charge offs	(4,487)		(95,834)
Gross up of allowance for PCD loans at acquisition			2,371
Provision for credit losses	(19,262)		178,569
Balance at end of period	325,578		349,327
Percent of Loans				2.10%	2.25%
Allowance for Loan and Lease Losses [Roll Forward]
Charge offs	(11,865)		(103,677)
Net Charge offs	(4,487)		(95,834)
Allowance for Loans Losses and Unfunded Commitments [Member] | Total commercial | Cumulative Effect, Period Of Adoption, Adjusted Balance
Allowance for credit losses on loans
Allowance for Credit Losses on Loans						262,482
Allowance for Loans Losses and Unfunded Commitments [Member] | Total commercial | First Staunton Bancshares [Member]
Allowance for credit losses on loans
Provision for credit losses			1,739
Allowance for Loans Losses and Unfunded Commitments [Member] | Total commercial | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Allowance for credit losses on loans
Allowance for Credit Losses on Loans						75,171
Allowance for Loans Losses and Unfunded Commitments [Member] | Residential mortgage
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Recoveries	134		500
Net Charge offs	(109)		(1,367)
Gross up of allowance for PCD loans at acquisition			651
Allowance for credit losses on loans
Balance at beginning of period	42,996	16,960	16,960
Allowance for Credit Losses on Loans	45,215	16,960	16,960	$ 45,215	$ 42,996
Recoveries	134		500
Net Charge offs	(109)		(1,367)
Gross up of allowance for PCD loans at acquisition			651
Provision for credit losses	2,328		(6,864)
Balance at end of period	45,215		42,996
Percent of Loans				0.59%	0.55%
Allowance for Loan and Lease Losses [Roll Forward]
Charge offs	(243)		(1,867)
Net Charge offs	(109)		(1,367)
Allowance for Loans Losses and Unfunded Commitments [Member] | Residential mortgage | Cumulative Effect, Period Of Adoption, Adjusted Balance
Allowance for credit losses on loans
Allowance for Credit Losses on Loans						50,175
Allowance for Loans Losses and Unfunded Commitments [Member] | Residential mortgage | First Staunton Bancshares [Member]
Allowance for credit losses on loans
Provision for credit losses			403
Allowance for Loans Losses and Unfunded Commitments [Member] | Residential mortgage | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Allowance for credit losses on loans
Allowance for Credit Losses on Loans						33,215
Allowance for Loans Losses and Unfunded Commitments [Member] | Home equity
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Recoveries	583		1,978
Net Charge offs	344		259
Gross up of allowance for PCD loans at acquisition			422
Allowance for credit losses on loans
Balance at beginning of period	21,967	11,964	11,964
Allowance for Credit Losses on Loans	21,967	11,964	21,967	$ 19,290	$ 21,967
Recoveries	583		1,978
Net Charge offs	344		259
Gross up of allowance for PCD loans at acquisition			422
Provision for credit losses	(3,021)		(5,358)
Balance at end of period	19,290		21,967
Percent of Loans				2.96%	3.11%
Allowance for Loan and Lease Losses [Roll Forward]
Charge offs	(238)		(1,719)
Net Charge offs	344		259
Allowance for Loans Losses and Unfunded Commitments [Member] | Home equity | Cumulative Effect, Period Of Adoption, Adjusted Balance
Allowance for credit losses on loans
Allowance for Credit Losses on Loans						26,204
Allowance for Loans Losses and Unfunded Commitments [Member] | Home equity | First Staunton Bancshares [Member]
Allowance for credit losses on loans
Provision for credit losses			440
Allowance for Loans Losses and Unfunded Commitments [Member] | Home equity | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Allowance for credit losses on loans
Allowance for Credit Losses on Loans						14,240
Allowance for Loans Losses and Unfunded Commitments [Member] | Other consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Recoveries	315		1,101
Net Charge offs	(511)		(3,689)
Gross up of allowance for PCD loans at acquisition			61
Allowance for credit losses on loans
Balance at beginning of period	17,187	7,044	7,044
Allowance for Credit Losses on Loans	13,631	7,044	7,044	$ 13,631	$ 17,187
Recoveries	315		1,101
Net Charge offs	(511)		(3,689)
Gross up of allowance for PCD loans at acquisition			61
Provision for credit losses	(3,044)		5,111
Balance at end of period	13,631		17,187
Percent of Loans				4.57%	5.49%
Allowance for Loan and Lease Losses [Roll Forward]
Charge offs	(827)		(4,790)
Net Charge offs	(511)		(3,689)
Allowance for Loans Losses and Unfunded Commitments [Member] | Other consumer | Cumulative Effect, Period Of Adoption, Adjusted Balance
Allowance for credit losses on loans
Allowance for Credit Losses on Loans						15,564
Allowance for Loans Losses and Unfunded Commitments [Member] | Other consumer | First Staunton Bancshares [Member]
Allowance for credit losses on loans
Provision for credit losses			140
Allowance for Loans Losses and Unfunded Commitments [Member] | Other consumer | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Allowance for credit losses on loans
Allowance for Credit Losses on Loans						8,520
Allowance for Loans Losses and Unfunded Commitments [Member] | Total consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Recoveries	1,031		3,579
Net Charge offs	(277)		(4,797)
Gross up of allowance for PCD loans at acquisition			1,134
Allowance for credit losses on loans
Balance at beginning of period	82,150	35,968	35,968
Allowance for Credit Losses on Loans	78,136	$ 35,968	35,968	$ 78,136	$ 82,150
Recoveries	1,031		3,579
Net Charge offs	(277)		(4,797)
Gross up of allowance for PCD loans at acquisition			1,134
Provision for credit losses	(3,738)		(7,112)
Balance at end of period	78,136		82,150
Percent of Loans				0.90%	0.92%
Allowance for Loan and Lease Losses [Roll Forward]
Charge offs	(1,308)		(8,376)
Net Charge offs	$ (277)		(4,797)
Allowance for Loans Losses and Unfunded Commitments [Member] | Total consumer | Cumulative Effect, Period Of Adoption, Adjusted Balance
Allowance for credit losses on loans
Allowance for Credit Losses on Loans						91,943
Allowance for Loans Losses and Unfunded Commitments [Member] | Total consumer | First Staunton Bancshares [Member]
Allowance for credit losses on loans
Provision for credit losses			$ 983
Allowance for Loans Losses and Unfunded Commitments [Member] | Total consumer | Accounting Standards Update 2016-13 | Cumulative Effect, Period Of Adoption, Adjustment
Allowance for credit losses on loans
Allowance for Credit Losses on Loans						$ 55,975