Note 6 - Allowance for Loan Losses - Allowance for Loan Losses on PCI Loans and Recorded Investment (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Acquired impaired loans evaluated for impairment	$ 61,247	$ 12,003
Allowance for acquired impaired loans
Commercial Portfolio Segment [Member]
Acquired impaired loans evaluated for impairment	41,167	5,273
Allowance for acquired impaired loans
Commercial Portfolio Segment [Member] | Waccamaw Commercial [Member]
Acquired impaired loans evaluated for impairment
Allowance for acquired impaired loans
Commercial Portfolio Segment [Member] | Peoples Commercial [Member]
Acquired impaired loans evaluated for impairment	4,371	4,405
Allowance for acquired impaired loans
Commercial Portfolio Segment [Member] | 1-4 family, Senior-commercial [Member]
Acquired impaired loans evaluated for impairment	4,564
Allowance for acquired impaired loans
Commercial Portfolio Segment [Member] | Construction and Land Development [Member]
Acquired impaired loans evaluated for impairment	1,956
Allowance for acquired impaired loans
Commercial Portfolio Segment [Member] | Farmland and Other Agricultural [Member]
Acquired impaired loans evaluated for impairment	3,722
Allowance for acquired impaired loans
Commercial Portfolio Segment [Member] | Multifamily [Member]
Acquired impaired loans evaluated for impairment	1,663
Allowance for acquired impaired loans
Commercial Portfolio Segment [Member] | Commercial Real Estate-owner Occupied [Member]
Acquired impaired loans evaluated for impairment	13,024
Allowance for acquired impaired loans
Commercial Portfolio Segment [Member] | Commercial Real Estate Non-owner Occupied [Member]
Acquired impaired loans evaluated for impairment	8,686
Allowance for acquired impaired loans
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Acquired impaired loans evaluated for impairment	2,829
Allowance for acquired impaired loans
Commercial Portfolio Segment [Member] | Other Commercial Loan [Member]
Acquired impaired loans evaluated for impairment	352	868
Allowance for acquired impaired loans
Consumer Real Estate Portfolio Segment [Member]
Acquired impaired loans evaluated for impairment	20,080	6,730
Allowance for acquired impaired loans
Consumer Real Estate Portfolio Segment [Member] | Waccamaw Serviced Home Equity Lines [Member]
Acquired impaired loans evaluated for impairment	2,121	5,017
Allowance for acquired impaired loans
Consumer Real Estate Portfolio Segment [Member] | Waccamaw Residential [Member]
Acquired impaired loans evaluated for impairment	587	788
Allowance for acquired impaired loans
Consumer Real Estate Portfolio Segment [Member] | 1-4 Family, Junior and HELOCS [Member]
Acquired impaired loans evaluated for impairment	2,157
Allowance for acquired impaired loans
Consumer Real Estate Portfolio Segment [Member] | 1-4 Family, Senior-consumer [Member]
Acquired impaired loans evaluated for impairment	13,174
Allowance for acquired impaired loans
Consumer Real Estate Portfolio Segment [Member] | Consumer Loan [Member]
Acquired impaired loans evaluated for impairment	1,341
Allowance for acquired impaired loans
Consumer Real Estate Portfolio Segment [Member] | Peoples Residential [Member]
Acquired impaired loans evaluated for impairment	700	925
Allowance for acquired impaired loans