Segment Reporting - Reconciliation of Revenue and Gross Profits from Segments to Consolidated (Details) - USD ($) $ in Millions			3 Months Ended		9 Months Ended
	Sep. 30, 2024	Feb. 29, 2024	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue			$ 671.2	$ 675.8	$ 2,002.9	$ 2,051.5
Cost of revenue			(541.3)	(538.3)	(1,616.9)	(1,649.8)
Loss from operations			(33.9)	(173.7)	(97.4)	(880.3)
Share-based compensation expense			(18.2)	(15.5)	(40.2)	(47.8)
Amortization of intangible assets			(37.5)	(38.7)	(112.5)	(116.0)
Impairment of goodwill			0.0	(141.7)	0.0	(714.9)
Impairment of assets, net			0.0	0.0	0.0	(20.0)
Interest expense			(21.2)	(18.0)	(61.9)	(80.1)
Gain on investments, net			0.1	0.1	0.3	0.2
Gain on debt extinguishment, net of debt modification costs			0.0	18.0	0.0	147.2
Other expense, net			(4.0)	(1.0)	(13.2)	(11.8)
Loss before income taxes			(59.0)	(174.6)	(172.2)	(824.8)
Operating Segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue			671.2	675.8	2,002.9	2,051.5
Loss from operations			81.2	89.3	237.2	248.1
Corporate And Reconciling Items
Segment Reporting, Revenue Reconciling Item [Line Items]
Loss from operations			49.2	57.1	152.3	181.6
Share-based compensation expense			(18.2)	(15.5)	(40.2)	(47.8)
Transaction-related adjustments, net			(0.2)	(1.8)	(2.1)	(4.4)
Restructuring and transformation expenses			(10.0)	(9.4)	(27.5)	(44.8)
Hosted Exchange incident expenses, net of proceeds received or expected to be received under our insurance coverage			0.0	1.2	0.0	1.1
Loss on contract termination						9.0
Public Cloud
Segment Reporting, Revenue Reconciling Item [Line Items]
Impairment of goodwill	$ (69.2)	$ (385.4)
Public Cloud | Operating Segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue			421.6	418.3	1,253.8	1,265.6
Cost of revenue			(329.0)	(322.5)	(979.7)	(988.1)
Other cost of revenue			(54.1)	(52.6)	(156.2)	(156.7)
Other segment items			(24.5)	(27.8)	(70.4)	(86.5)
Loss from operations			14.0	15.4	47.5	34.3
Private Cloud
Segment Reporting, Revenue Reconciling Item [Line Items]
Impairment of goodwill	$ (72.5)	$ (187.8)
Private Cloud | Operating Segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue			249.6	257.5	749.1	785.9
Cost of revenue			(154.6)	(158.2)	(469.5)	(485.3)
Other segment items			(27.8)	(25.4)	(89.9)	(86.8)
Loss from operations			$ 67.2	$ 73.9	$ 189.7	$ 213.8