Consolidated Statements of Changes in Stockholders' Equity - USD ($)	Total	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]
BALANCE at Dec. 31, 2014	$ 55,887,787	$ 12,000	$ 2,965,783	$ 42,508,429	$ 10,704,776	$ (303,201)
BALANCE (in shares) at Dec. 31, 2014		12,000	2,965,783
Net income	1,509,712	$ 0	$ 0	0	1,509,712	0
Other comprehensive loss	(48,920)	0	0	0	0	(48,920)
Issuance of common stock	15,000,004	$ 0	$ 1,000,003	14,000,001	0	0
Issuance of common stock (in shares)		0	1,000,003
Issuance of stock grants	100,216		$ 6,659	93,557
Issuance of stock grants (in shares)			6,659
Stock issuance costs	(840,418)			(840,418)
Exercise of stock options	213,542		$ 24,292	189,250
Exercise of stock options (in shares)			24,292
Shares retained by shareholders of Cornerstone Bancshares, Inc.	28,435,075		$ 1,660,836	26,774,239
Shares retained by shareholders of Cornerstone Bancshares, Inc. (in shares)			1,660,836
Conversion shares issued to shareholders of SmartFinancial, Inc.	0		$ 148,904	(148,904)
Conversion shares issued to shareholders of SmartFinancial, Inc. (in shares)			148,904
Dividends on preferred stock	(120,000)	$ 0	$ 0	0	(120,000)	0
Stock option compensation expense	39,861	0	0	39,861	0	0
BALANCE at Dec. 31, 2015	100,176,859	$ 12,000	$ 5,806,477	82,616,015	12,094,488	(352,121)
BALANCE (in shares) at Dec. 31, 2015		12,000	5,806,477
Net income	5,798,808	$ 0	$ 0	0	5,798,808	0
Other comprehensive loss	(650,119)	0	0	0	0	(650,119)
Exercise of stock options	803,957	$ 0	$ 89,556	714,401	0	0
Exercise of stock options (in shares)		0	89,556
Dividends on preferred stock	(1,022,000)	$ 0	$ 0	0	(1,022,000)	0
Stock option compensation expense	132,635	0	0	132,635	0	0
BALANCE at Dec. 31, 2016	$ 105,240,140	$ 12,000	$ 5,896,033	$ 83,463,051	$ 16,871,296	$ (1,002,240)
BALANCE (in shares) at Dec. 31, 2016		12,000	5,896,033