CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	3 Months Ended			9 Months Ended		12 Months Ended
	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018	Jun. 30, 2018	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2017
Cash flows from operating activities
Net income	$ 34.7		$ 23.5	$ 87.0	$ 60.0
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	161.2		190.9	475.9	570.4
Loss on extinguishment of debt					4.9
Gain on sale of SRT				(5.5)
Non-cash interest expense				7.6	9.7
Stock-based compensation	27.0		19.2	79.9	70.5
Amortization of deferred revenue				(112.9)	(100.3)
Foreign currency loss/(gain) on intercompany loans	(7.1)		(13.9)	5.8	(27.8)
Deferred income taxes				37.1	39.0
Provision for bad debts				8.7	5.8
Non-cash loss on investments	0.2		0.1	0.8	0.5
Changes in operating assets and liabilities, net of acquisitions
Trade receivables				5.5	(33.7)
Accounts payable and accrued liabilities				19.2	23.7
Additions to deferred revenue				138.7	138.0
Other assets and liabilities				(21.8)	(41.2)
Net cash provided by operating activities				726.0	719.5
Cash flows from investing activities
Purchases of property and equipment	(206.4)		(195.1)	(591.1)	(581.9)
Cash paid for acquisitions, net of cash acquired					(155.3)
Proceeds from sale of SRT, net of cash held in escrow				39.0
Other					(0.2)
Net cash used in investing activities				(552.1)	(737.4)
Cash flows from financing activities
Proceeds from debt				275.0	462.8
Principal payments on long-term debt				(108.8)	(314.4)
Principal payments on capital lease obligations				(5.6)	(6.4)
Payment of debt issue costs					(4.2)
Common stock repurchases				(402.5)
Cash paid for Santa Clara acquisition financing arrangement and other				(5.8)	(3.8)
Net cash (used in)/provided by financing activities				(247.7)	134.0
Net cash flows				(73.8)	116.1
Effect of changes in foreign exchange rates on cash				(6.6)	(7.3)
Net (decrease)/increase in cash, cash equivalents and restricted cash				(80.4)	108.8
Cash, cash equivalents and restricted cash, beginning of year		$ 334.0		261.3	225.2	$ 225.2
Cash, cash equivalents and restricted cash, end of period	180.9	261.3	334.0	180.9	334.0	261.3
Supplemental disclosure of non-cash investing and financing activities:
Cash paid for interest, net of capitalized interest				222.8	195.1
Cash paid for income taxes				3.5	16.9
Non-cash purchases of equipment through capital leasing				53.0	18.2
Non-cash purchases of equipment through nonmonetary exchange				35.7	10.7
Decrease in accounts payable and accrued expenses for purchases of property and equipment				(16.3)	(45.8)
Cash and cash equivalents							$ 179.7	$ 256.7	$ 329.3	$ 220.7
Restricted cash included in other assets							1.2	4.6	4.7	4.5
Total cash, cash equivalents and restricted cash	$ 180.9	$ 334.0	$ 334.0	$ 261.3	$ 225.2	$ 225.2	$ 180.9	$ 261.3	$ 334.0	$ 225.2