DEBT - SUMMARY (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Debt
Capital leases		$ 0.1
Total Debt	$ 868.1	856.4
Less current portion	(45.2)	(42.1)
Total Long-term Debt	822.9	814.3
5.79%, payable through 2020
Debt
Total Debt	$ 10.5	$ 10.5
Interest rate (as a percent)	5.79%	5.79%
3.66%, payable through 2023
Debt
Total Debt	$ 41.0	$ 41.0
Interest rate (as a percent)	3.66%	3.66%
4.16%, payable through 2027
Debt
Total Debt	$ 44.5	$ 44.5
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	$ 194.0	$ 200.0
Interest rate (as a percent)	3.14%	3.14%
4.31%, payable through 2032
Debt
Total Debt	$ 32.7	$ 32.7
Interest rate (as a percent)	4.31%	4.31%
4.35%, payable through 2044
Debt
Total Debt	$ 100.0	$ 100.0
Interest rate (as a percent)	4.35%	4.35%
3.92%, payable through 2045
Debt
Total Debt	$ 71.4	$ 71.4
Interest rate (as a percent)	3.92%	3.92%
5.34%, payable through 2028
Debt
Total Debt	$ 20.9	$ 22.0
Interest rate (as a percent)	5.34%	5.34%
5.27%, payable through 2029
Debt
Total Debt	$ 23.1	$ 24.2
Interest rate (as a percent)	5.27%	5.27%
Revolving Credit Facility
Debt
Total Debt	$ 255.0	$ 235.0
Funds available under the revolving credit facility	$ 246.5
Interest rate during period (as a percent)	3.97%