CONTRIBUTING EMPLOYEE OWNERSHIP PLAN (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Defined Contribution Plan Disclosure [Line Items]
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 6.9	$ 6.7	$ 16.3	$ 15.3
Employer matching contributions to employee ownership plan	$ 4.0	$ 3.7	$ 7.9	$ 7.4
Minimum
Defined Contribution Plan Disclosure [Line Items]
Contribution To Individual Retirement Account Percentage Of Employees Eligible Compensation	5.00%		5.00%
Maximum
Defined Contribution Plan Disclosure [Line Items]
Contribution To Individual Retirement Account Percentage Of Employees Eligible Compensation	7.50%		7.50%