Loans and Asset Quality Information (Summary of Nonperforming Assets) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Oct. 01, 2017	Mar. 03, 2017
Loans and Leases Receivable Disclosure [Line Items]
Nonaccrual loans	$ 34,922	$ 24,866
Total loans	4,770,063	4,453,466	$ 4,339,497
Foreclosed properties	2,987	3,873
Purchased credit impaired loans not included above	9,742	12,664
Purchased Impaired Loans
Loans and Leases Receivable Disclosure [Line Items]
Recorded loans with a fair value				$ 9,900	$ 19,300
Purchased Impaired Loans | Carolina Bank Holdings, Inc. | Accruing 90 Days or More Past Due
Loans and Leases Receivable Disclosure [Line Items]
Recorded loans with a fair value	800	800
Nonperforming assets
Loans and Leases Receivable Disclosure [Line Items]
Nonaccrual loans	34,922	24,866
Restructured loans - accruing	9,867	9,053
Accruing loans 90 days past due	0	0
Total loans	44,789	33,919
Foreclosed properties	2,987	3,873
Total nonperforming assets	$ 47,776	$ 37,792