STOCK-BASED COMPENSATION PLAN - Nonvested Restricted Stock Awards and Fair Value Assumptions (Details)	6 Months Ended
	Jun. 30, 2022 $ / shares shares
Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding (in shares) | shares	32,003
Fair value per share (in dollars per share) | $ / shares	$ 33.90
2020 - TSR | Officers & Key Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding (in shares) | shares	31,957
Fair value per share (in dollars per share) | $ / shares	$ 25.51
Expected Volatility	34.80%
Risk-Free Interest Rate	0.21%
2020 - CEGR, Time | Officers & Key Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding (in shares) | shares	80,644
Fair value per share (in dollars per share) | $ / shares	$ 25.19
2021 - TSR | Officers & Key Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding (in shares) | shares	35,091
Fair value per share (in dollars per share) | $ / shares	$ 28.11
Expected Volatility	39.90%
Risk-Free Interest Rate	0.27%
2021 - CEGR, Time | Officers & Key Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding (in shares) | shares	132,543
Fair value per share (in dollars per share) | $ / shares	$ 25.33
2022 - TSR | Officers & Key Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding (in shares) | shares	37,608
Fair value per share (in dollars per share) | $ / shares	$ 35.05
Expected Volatility	43.50%
Risk-Free Interest Rate	1.80%
2022 - CEGR, Time | Officers & Key Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding (in shares) | shares	147,327
Fair value per share (in dollars per share) | $ / shares	$ 35.05