Credit Facilities - Federal Home Loan Bank Advances (Details) - Federal Home Loan Bank of Atlanta - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Advances from Federal Home Loan Banks
Credit facility from FHLB	$ 311,200
Remaining credit availability	221,500
Outstanding balance - Advances	89,666	$ 96,830
Average short-term borrowings	45,000	9,300
Principal balances outstanding on pledged loans	241,900	223,500
FHLB 1.31% Fixed Rate Hybrid Advance Maturing April 2020
Advances from Federal Home Loan Banks
Outstanding balance - Advances	$ 12,000
Fixed Interest rate	1.31%
FHLB 0.30% Fixed Rate Hybrid Advance 1 Maturing April 2020
Advances from Federal Home Loan Banks
Outstanding balance - Advances	$ 6,000
Fixed Interest rate	0.30%
FHLB 0.30% Fixed Rate Hybrid Advance 2 Maturing April 2020
Advances from Federal Home Loan Banks
Outstanding balance - Advances	$ 3,200
Fixed Interest rate	0.30%
FHLB 2.09% Fixed Rate Hybrid Advance Maturing June 2020
Advances from Federal Home Loan Banks
Outstanding balance - Advances	$ 15,000
Fixed Interest rate	2.09%
FHLB 3.04% Fixed Rate Hybrid Advance Maturing November 2020
Advances from Federal Home Loan Banks
Outstanding balance - Advances	$ 5,000	$ 5,000
Fixed Interest rate	3.04%	3.04%
FHLB 2.91% Fixed Rate Hybrid Advance Maturing November 2020
Advances from Federal Home Loan Banks
Outstanding balance - Advances	$ 5,000	$ 5,000
Fixed Interest rate	2.91%	2.91%
FHLB 2.44% Fixed Rate Hybrid Advance Maturing April 2021
Advances from Federal Home Loan Banks
Outstanding balance - Advances	$ 6,000	$ 6,000
Fixed Interest rate	2.44%	2.44%
FHLB 2.68% Convertible Rate Advance Maturing May 2021
Advances from Federal Home Loan Banks
Outstanding balance - Advances	$ 10,000	$ 10,000
Fixed Interest rate	2.68%	2.68%
FHLB 3.15% Fixed Rate Hybrid Advance Maturing October 2022
Advances from Federal Home Loan Banks
Outstanding balance - Advances	$ 5,000	$ 5,000
Fixed Interest rate	3.15%	3.15%
FHLB 1.62% Principal Reducing Credit Advance Maturing March 2023
Advances from Federal Home Loan Banks
Outstanding balance - Advances	$ 1,286	$ 1,393
Fixed Interest rate	1.62%	1.62%
FHLB 1.29% Fixed Rate Hybrid Advance 1 Maturing March 2024
Advances from Federal Home Loan Banks
Outstanding balance - Advances	$ 9,900
Fixed Interest rate	1.29%
FHLB 1.29% Fixed Rate Hybrid Advance 2 Maturing March 2024
Advances from Federal Home Loan Banks
Outstanding balance - Advances	$ 9,900
Fixed Interest rate	1.29%
FHLB 1.99% Principal Reducing Credit Advance Maturing March 2026
Advances from Federal Home Loan Banks
Outstanding balance - Advances	$ 1,380	$ 1,437
Fixed Interest rate	1.99%	1.99%
FHLB 1.73% Fixed Rate Advance Maturing January 2020
Advances from Federal Home Loan Banks
Outstanding balance - Advances		$ 12,000
Fixed Interest rate		1.73%
FHLB 1.76% Fixed Rate Advance Maturing January 2020
Advances from Federal Home Loan Banks
Outstanding balance - Advances		$ 4,500
Fixed Interest rate		1.76%
FHLB 1.68% Fixed Rate Advance 1 Maturing January 2020
Advances from Federal Home Loan Banks
Outstanding balance - Advances		$ 7,600
Fixed Interest rate		1.68%
FHLB 1.68% Fixed Rate Advance 2 Maturing January 2020
Advances from Federal Home Loan Banks
Outstanding balance - Advances		$ 7,700
Fixed Interest rate		1.68%
FHLB 1.70% Fixed Rate Advance 1 Maturing January 2020
Advances from Federal Home Loan Banks
Outstanding balance - Advances		$ 6,000
Fixed Interest rate		1.70%
FHLB 1.70% Fixed Rate Advance 2 Maturing January 2020
Advances from Federal Home Loan Banks
Outstanding balance - Advances		$ 7,000
Fixed Interest rate		1.70%
FHLB 1.71% Fixed Rate Advance Maturing January 2020
Advances from Federal Home Loan Banks
Outstanding balance - Advances		$ 3,200
Fixed Interest rate		1.71%
FHLB 1.51% Fixed Rate Hybrid Advance Maturing June 2019
Advances from Federal Home Loan Banks
Outstanding balance - Advances		$ 15,000
Fixed Interest rate		1.51%