Financial Information of Colony Bankcorp, Inc. (Parent Only) - Statements of Cash Flows, Parent Company (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 11,815	$ 10,211
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation expense	33	34
Net cash (used in) provided by operating activities	(19,094)	3,877
CASH FLOWS FROM INVESTING ACTIVITIES
Purchase of premises and equipment	(4,241)	(3,485)
Proceeds from sale of premises and equipment	1,035	690
Net cash and cash equivalents paid in acquisition	0	(467)
Net cash (used in) provided by investing activities	(130,266)	6,802
CASH FLOWS FROM FINANCING ACTIVITIES
Dividends paid for common stock	(3,800)	(2,692)
Net cash (used in) provided by financing activities	228,774	33,257
Net increase (decrease) in cash and cash equivalents	79,414	43,936
Cash and cash equivalents at beginning of period	104,092	60,156
Cash and cash equivalents at end of period	183,506	104,092
Parent Company
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	11,815	10,211
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	70	81
Stock-based compensation expense	33	34
Equity in undistributed earnings of subsidiaries	(7,404)	(5,972)
Change in interest payable	(51)	21
Other	(354)	1,065
Net cash (used in) provided by operating activities	4,109	5,440
CASH FLOWS FROM INVESTING ACTIVITIES
Purchase of premises and equipment	0	(54)
Proceeds from sale of premises and equipment	1,314	0
Net cash and cash equivalents paid in acquisition	0	(16,145)
Net cash (used in) provided by investing activities	1,314	(16,199)
CASH FLOWS FROM FINANCING ACTIVITIES
Net increase (decrease) in other borrowed money	(1,000)	14,563
Dividends paid for common stock	(3,800)	(2,692)
Net cash (used in) provided by financing activities	(4,800)	11,871
Net increase (decrease) in cash and cash equivalents	623	1,112
Cash and cash equivalents at beginning of period	2,049	937
Cash and cash equivalents at end of period	$ 2,672	$ 2,049