SHARE-BASED PAYMENTS (Tables)

12 Months Ended

Dec. 31, 2021

Share-based Payments [Line Items]

Schedule of Share-based Compensation, Restricted Stock Units Activity

The following tables set forth activity and various statistics for restricted stock unit awards outstanding under the respective plans for the period indicated:

	Number of Units	Weighted- Average Grant Date Fair Value
Nonvested at December 31, 2020	99,800	$	82.29
Granted	50,353	$	72.69
Vested	(42,821)	$	71.67
Forfeited	(13,058)	$	81.07
Nonvested at December 31, 2021	94,274	$	82.16

	2021		2020		2019
Weighted-average grant date fair value (per share)	$	72.69	$	96.21	$	83.94
Fair value of shares granted (thousands of dollars)	$	3,660	$	3,005	$	3,001

Schedule of Nonvested Performance-based Units Activity

The following tables set forth activity and various statistics related to our performance stock unit awards and the assumptions used by us in the valuations of the 2021, 2020 and 2019 grants at the grant date:

	Number of Units	Weighted- Average Grant Date Fair Value
Nonvested at December 31, 2020	208,520	$	87.97
Granted	107,381	$	82.51
Vested	(76,483)	$	74.04
Forfeited	(40,819)	$	89.19
Nonvested at December 31, 2021	198,599	$	90.13

	2021	2020	2019
Volatility (a)	32.70%	16.40%	18.70%
Dividend yield	3.19%	2.25%	2.38%
Risk-free interest rate (b)	0.20%	1.40%	2.50%

(a) - Volatility based on historical volatility over three years using daily stock price observations of our peer utilities.

(b) - Using 3-year treasury.

	2021		2020		2019
Weighted-average grant date fair value (per share)	$	82.51	$	102.77	$	89.86
Fair value of shares granted (thousands of dollars)	$	8,860	$	6,502	$	6,401