LEASES - Lease cost (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Lease Cost:
Operating lease cost	$ 19.8	$ 25.4	$ 39.0	$ 51.8
Short-term lease cost	0.2	0.7	0.4	1.3
Variable lease cost	16.4	10.0	30.3	20.3
Sublease income	(3.0)	(2.4)	(4.5)	(4.6)
Net lease cost	33.4	33.7	65.2	68.8
Other information:
Operating cash outflows from operating leases	(48.5)	(24.8)	(79.9)	(51.4)
Right-of-use assets obtained in exchange for lease obligations	$ 2.8	$ 23.8	$ 10.8
Right-of-use assets obtained in exchange for lease obligations				$ (2.3)
Weighted-average remaining lease term - real estate	6 years 4 months 24 days	7 years 6 months	6 years 4 months 24 days	7 years 6 months
Weighted-average discount rate - real estate leases	3.49%	3.23%	3.49%	3.23%