Acquisition (Details) $ / shares in Units, $ in Thousands	3 Months Ended	6 Months Ended	9 Months Ended	12 Months Ended
	Jun. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2019 USD ($)	Dec. 31, 2018 USD ($) shares	May 31, 2018 $ / shares
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares | shares				3,253,060
Assets		$ 1,636,927	$ 1,644,447	$ 1,636,927
Interest-bearing demand deposits		1,730	4,452	1,730
Liabilities		1,417,942	1,418,955	1,417,942
Deposits		1,300,919	1,355,383	1,300,919
Goodwill		59,221	59,221	59,221
Business Acquisition, Share Price | $ / shares					$ 0.1955
Columbus First Bancorp, Inc. [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Less common stock issued	$ 63,598	63,598		63,598
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Equity Interests		0
Less cash paid for the common stock	783			783
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Payments To Acquire Business, Gross		0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents	13,679	13,679		13,679
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Cash and Equivalents		0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Financial Assets	10,350	10,350		10,350
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Assets		0
Number of branches					1
Equity interest exchange ratio					2
Business combination, consideration transferred	64,381			64,381
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Consideration Transferred		0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Federal Home Loan Bank Stock	1,207	1,207		1,207
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Federal Home Loan Bank Stock		0
Business Combination, Acquired Receivable, Fair Value	282,748	282,133		282,133
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Loans Receivable		(615)
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Loan Receivables Held For Sale	1,819	1,819		1,819
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Loan Receivables Held For Sale		0
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Property, Plant, and Equipment		0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment	102	102		102
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	2,089	2,177		2,177
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles		88
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Real Estate Owned	35	35		35
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Other Real Estate Owned		0
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Assets	0	352		352
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Deferred Tax Assets		352
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets	2,022	1,364		1,364
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Other Noncurrent Assets		(658)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	314,051	313,218		313,218
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Assumed Assets		(833)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Financial Liabilities	245,036	244,430		244,430
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Liabilities		(606)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt	22,920	22,943		22,943
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Current Liabilities, Long-Term Debt		23
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Short-term Borrowings	10,000	10,000		10,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Current Liabilities, Short-Term Borrowings		0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent	200	0		0
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Deferred Tax Liabilities		(200)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other	491	502		502
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Noncurrent Liabilities, Other		11
Liabilities assumed	278,647	277,875		277,875
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Assumed Liabilities		(772)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net	35,404	35,343		35,343
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Recognized Identifiable Assets Acquired And Liabilities Assumed, Net		(61)	$ 0
Goodwill	$ 28,977	29,038		$ 29,038
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Goodwill		$ 61