DEBT - SUMMARY (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Debt
Total Debt	$ 890.0	$ 958.4
Less current portion	(50.5)	(48.4)
Total Long-term Debt	839.5	910.0
Less: Deferred loan fees	(16.0)
Total Long-term Debt, net of deferred loan fees	$ 823.5	910.0
5.79%, payable through 2020
Debt
Total Debt		$ 3.5
Interest rate (as a percent)	5.79%	5.79%
3.66%, payable through 2023
Debt
Total Debt	$ 27.4	$ 31.9
Interest rate (as a percent)	3.66%	3.66%
4.16%, payable through 2027
Debt
Total Debt	$ 36.7	$ 39.3
Interest rate (as a percent)	4.16%	4.16%
3.37 %, payable through 2027
Debt
Total Debt	$ 75.0	$ 75.0
Interest rate (as a percent)	3.37%	3.37%
3.14%, payable through 2031
Debt
Total Debt	$ 178.8	$ 188.0
Interest rate (as a percent)	3.14%	3.14%
4.31%, payable through 2032
Debt
Total Debt	$ 29.0	$ 30.3
Interest rate (as a percent)	4.31%	4.31%
4.35%, payable through 2044
Debt
Total Debt		$ 100.0
Interest rate (as a percent)	4.35%	4.35%
3.92%, payable through 2045
Debt
Total Debt		$ 69.5
Interest rate (as a percent)	3.92%	3.92%
5.34%, payable through 2028
Debt
Total Debt	$ 18.7	$ 19.8
Interest rate (as a percent)	5.34%	5.34%
5.27%, payable through 2029
Debt
Total Debt	$ 20.9	$ 22.0
Interest rate (as a percent)	5.27%	5.27%
1.22 %, payable through 2043
Debt
Total Debt	$ 185.9
Interest rate (as a percent)	1.22%
1.35 %, payable through 2044
Debt
Total Debt	$ 139.6
Interest rate (as a percent)	1.35%
Revolving Credit Facility
Debt
Total Debt	$ 178.0	$ 379.1
Funds available under the revolving credit facility	$ 433.2
Interest rate during period (as a percent)	3.25%