STOCK-BASED COMPENSATION - NON-OPTIONS (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended			30 Months Ended
	Dec. 31, 2021	Dec. 31, 2023	Dec. 31, 2022	Jun. 30, 2021	Dec. 31, 2023
Other stock-based compensation
Contractual term of awards		10 years
Minimum
Other stock-based compensation
Continuous service period for awards to vest		1 year
Maximum
Other stock-based compensation
Continuous service period for awards to vest		3 years
Restricted stock
Non-vested other than stock options, number of shares
Outstanding at the beginning of the period (in shares)		120,542
Granted (in shares)		56,710
Vested (in shares)		(41,139)
Outstanding at the end of the period (in shares)		136,113	120,542		136,113
Other than stock options, weighted-average grant date fair value
Non-vested at the beginning of the period (in dollars per share)		$ 116.76
Granted (in dollars per share)		120.67
Vested (in dollars per share)		115.24
Non-vested at the end of the period (in dollars per share)		$ 118.84	$ 116.76		$ 118.84
Restricted stock | Officers and Certain Employees
Non-vested other than stock options, number of shares
Granted (in shares)		49,480
Other stock-based compensation
Vesting period	3 years	3 years	3 years	3 years
Holding period of awards as a vesting condition				2 years
Restricted stock | Non Executive Directors
Non-vested other than stock options, number of shares
Granted (in shares)		7,230
Other stock-based compensation
Vesting period		1 year
Vesting (as a percent)		50.00%
Percentage of shares granted to non-executive directors, vesting one year after date of grant		50.00%			50.00%
Performance stock
Non-vested other than stock options, number of shares
Outstanding at the beginning of the period (in shares)		166,441
Granted (in shares)		82,740
Exercised (in shares)		(5,847)
Non-attainment (in shares)		(27,143)
Outstanding at the end of the period (in shares)		216,191	166,441		216,191
Other than stock options, weighted-average grant date fair value
Non-vested at the beginning of the period (in dollars per share)		$ 122.05
Granted (in dollars per share)		139.50
Exercised (in dollars per share)		82.30
Non-attainment (in dollars per share)		79.84
Non-vested at the end of the period (in dollars per share)		$ 135.11	$ 122.05		$ 135.11
Other stock-based compensation
Earn out basis if no goals are met (as a percent)				0.00%
Earn out basis if some goals are met (as a percent)				100.00%
Earn out basis if all goals are met (as a percent)		200.00%		200.00%	200.00%
Gold Equivalent Ounces Shares
Other stock-based compensation
Contractual term of awards				5 years
Total Shareholder Return Shares
Other stock-based compensation
Contractual term of awards				3 years	3 years
Continuous service period for awards to vest		3 years		3 years	3 years
Earn out basis if no goals are met (as a percent)		0.00%			0.00%
Earn out basis if some goals are met (as a percent)		100.00%			100.00%
Earn out basis if all goals are met (as a percent)		200.00%			200.00%
Stock Appreciation Rights (SARs) [Member]
Non-vested other than stock options, number of shares
Outstanding at the beginning of the period (in shares)		174,906
Granted (in shares)	0	0	0
Exercised (in shares)	0	(17,627)
Outstanding at the end of the period (in shares)		157,279	174,906		157,279
Exercisable at the end of the period (in shares)		157,279			157,279
Other than stock options, weighted-average grant date fair value
Non-vested at the beginning of the period (in dollars per share)		$ 111.65
Exercised (in dollars per share)		99.34
Non-vested at the end of the period (in dollars per share)		113.03	$ 111.65		$ 113.03
Exercisable at the end of the period (in dollars per share)		$ 113.03			$ 113.03
Other than stock options, weighted-average remaining contractual life (in years)
Outstanding at the end of the period		5 years 2 months 12 days
Exercisable at the end of the period		5 years 2 months 12 days
Aggregate Intrinsic Value
Intrinsic value on outstanding shares		$ 2,526			$ 2,526
Intrinsic value on exercisable shares		2,526			$ 2,526
Other stock-based compensation
Total intrinsic value		$ 700	$ 200	$ 100