EMPLOYEE BENEFIT PLANS (Changes in Benefit Obligations, Fair Value of Plan Assets, and Funded Status of Plan) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Pension Benefits [Member]
Change in benefit obligation:
Benefit obligation at beginning of year	$ 329.3	$ 271.2
Service cost	57.5	59.0	$ 43.6
Interest cost	5.3	6.9	8.3
Plan amendments	0.0	0.0
Benefit payments	(31.2)	(18.0)
Actuarial (gain) loss	(7.6)	10.2
Projected benefit obligation at end of year	353.3	329.3	271.2
Change in plan assets:
Fair value of plan assets at beginning of year	255.8	197.4
Actual return on plan assets	27.7	28.6
Benefits paid	(31.2)	(18.0)
Employer contributions	54.0	47.8
Fair value of plan assets at end of year	306.3	255.8	197.4
Reconciliation of funded status:
Fair value of plan assets at end of year	306.3	255.8	197.4
Less benefit obligations at end of year	353.3	329.3	271.2
Funded status at end of year	(47.0)	(73.5)
Post Retirement Medical Plan [Member]
Change in benefit obligation:
Benefit obligation at beginning of year	22.0	17.5
Service cost	1.1	1.0	1.0
Interest cost	0.3	0.4	0.7
Plan amendments	0.0	1.8
Benefit payments	(1.2)	(0.6)
Actuarial (gain) loss	(4.0)	1.9
Projected benefit obligation at end of year	18.2	22.0	17.5
Change in plan assets:
Fair value of plan assets at beginning of year	0.0	0.0
Actual return on plan assets	0.0	0.0
Benefits paid	(1.2)	(0.6)
Employer contributions	1.2	0.6
Fair value of plan assets at end of year	0.0	0.0	0.0
Reconciliation of funded status:
Fair value of plan assets at end of year	0.0	0.0	0.0
Less benefit obligations at end of year	18.2	22.0	$ 17.5
Funded status at end of year	$ (18.2)	$ (22.0)