Loans (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Apr. 01, 2019	Jul. 01, 2018
Financing Receivable, Credit Quality Indicator [Line Items]
Business Combination, Acquired Receivable, Fair Value						$ 578,577,000
Business Combination, Acquired Receivables, Gross Contractual Amount						589,698,000	$ 277,900,000
Loans and Leases Receivable, Deferred Income	$ 30,800,000		$ 30,800,000		$ 16,300,000
Goodwill, Purchase Accounting Adjustments			8,100,000		11,700,000
Troubled Debt Restructuring, Classification removed	709,000	$ 15,000	1,600,000	$ 38,000
Partial Charge-Offs On Impaired Loans			563,000		719,000
Impaired Financing Receivable, Related Allowance	8,666,000		8,666,000		5,230,000
Recorded investment, related to loans	34,100,000		34,100,000		12,700,000
Troubled Debt Restructuring Included In Nonaccrual Loans	22,900,000		22,900,000		34,300,000
TDRs included in accruing loan totals	23,900,000		23,900,000		21,300,000
Nonaccrual Trouble Debt Restructuring Current	12,500,000		12,500,000		23,200,000
Commitments to lend additional funds to borrowers whose terms had been modified in a TDR	4,700,000		4,700,000		7,900,000
Specific reserves related to troubled debt restructuring	2,000,000.0		2,000,000.0		2,200,000
Additional Specific Reserves Related To Troubled Debt Restructuring			0	0
Financing Receivable, Modifications, Recorded Investment, During Period	1,506,000	7,866,000	7,390,000	16,229,000
Loan Modifications on Nonacrrual status	100,000	600,000	$ 400,000	1,800,000
Loan past due period before entering default status			30 days
Financing Receivable, Modifications, Subsequent Default, Recorded Investment, During Period	700,000	900,000	$ 1,600,000	1,200,000
Deposit Liabilities Reclassified as Loans Receivable	4,800,000		4,800,000		2,200,000
PPP loans originated [Line Items]	542,800,000
SBA Fees received			20,200,000
SBA PPP Fees recognized	3,800,000		6,600,000
PPP loans receivable [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Deferred Income	13,600,000		13,600,000
Financing Receivable With No Related Allowance Recorded [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Partial Charge-Offs On Impaired Loans			400,000		500,000
Financing Receivable With A Related Allowance Recorded [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Partial Charge-Offs On Impaired Loans			197,000		210,000
Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period	359,000	241,000	3,204,000	3,236,000
Commercial Real Estate [Member] | Financing Receivable With No Related Allowance Recorded [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Impaired Financing Receivable, Related Allowance	0		0		0
Commercial Real Estate [Member] | Financing Receivable With A Related Allowance Recorded [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Impaired Financing Receivable, Related Allowance	3,014,000		3,014,000		35,000
Accruing [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period	435,000	1,745,000	2,449,000	4,943,000
Loans modified during period	65,000	48,000	621,000	87,000
Accruing [Member] | Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period			1,136,000
Nonaccrual [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period	1,071,000	6,121,000	4,941,000	11,286,000
Loans modified during period	700,000	900,000	900,000	1,100,000
Nonaccrual [Member] | Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period	359,000	241,000	2,068,000	3,236,000
Consumer [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period	16,700,000	11,900,000	58,200,000	21,400,000
Commercial Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period		$ 400,000	0	$ 600,000
Financing Receivables, COVID Modifications, Recorded Investment, During Period			583,700,000
Commercial Portfolio Segment [Member] | Covid Restructuring [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivables, COVID Modifications, Recorded Investment, During Period			112,000
Commercial Portfolio Segment [Member] | Other Restructuring [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivables, COVID Modifications, Recorded Investment, During Period			6,000,000.0
Consumer Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivables, COVID Modifications, Recorded Investment, During Period			111,000,000.0
Consumer Loan [Member] | Covid Restructuring [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivables, COVID Modifications, Recorded Investment, During Period			818,000
Consumer Loan [Member] | Other Restructuring [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivables, COVID Modifications, Recorded Investment, During Period			2,300,000
Financial Asset Acquired with Credit Deterioration [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Business Combination, Acquired Receivable, Fair Value	1,700,000		1,700,000		3,000,000.0	18,400,000	4,900,000
Business Combination, Acquired Receivables, Gross Contractual Amount	1,800,000		1,800,000		3,200,000	$ 19,900,000	$ 5,100,000
NewDominion [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Allowance for Loan and Lease Losses, Loans Acquired			2,000		101,000
Carolina Alliance [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Business Combination, Acquired Receivable, Fair Value	10,200,000		10,200,000		11,300,000
Business Combination, Acquired Receivables, Gross Contractual Amount	$ 12,500,000		12,500,000		13,800,000
Allowance for Loan and Lease Losses, Loans Acquired			$ 101,000		$ 167,000