ACQUISITIONS AND DISPOSITIONS (Scott-Rice Telephone Co.) (Details) - Scott Rice Telephone Co. - USD ($) $ in Millions		4 Months Ended	12 Months Ended
	Jul. 31, 2018	Jun. 30, 2017	Jun. 30, 2018	Sep. 30, 2018
Dispositions
Consideration received for disposal	$ 42.2
Purchase price, held in escrow				$ 3.2
Pre-tax gain on sale	$ 5.5
Pre-tax income (loss)		$ 2.9	$ (1.6)
Assets held for sale:
Property and equipment, net			35.7
Goodwill			5.2
Other assets			0.9
Total assets held for sale			41.8
Liabilities associated with assets held for sale:
Deferred tax liability, net			5.1
Other liabilities			1.0
Total liabilities associated with assets held for sale			$ 6.1