Segment Information - Segment Information By Revenue Type (Details) - USD ($) $ in Millions		1 Months Ended	2 Months Ended	3 Months Ended		7 Months Ended		9 Months Ended
	Aug. 11, 2023	Aug. 11, 2023	Sep. 30, 2023	Jun. 30, 2023	Sep. 30, 2022	Aug. 11, 2023		Sep. 30, 2022
Segment Reporting Information [Line Items]
Revenues		$ (351.6)	$ (591.8)		$ (810.4)	$ (2,131.9)		$ (2,491.9)
Operating profit (loss)		0.5	36.9		5.5	(5.5)		(169.4)
Impairment of assets		0.6	1.1		4.1	3.3		64.7
Amortization of Wincor Nixdorf purchase accounting intangible assets			0.0			41.8		52.8
Severance accrual		5.3	6.2		20.7	38.9		98.9
Other income (expense)		2,239.7	(77.0)		(51.5)	1,453.9		(142.1)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest, Total		2,240.2	(40.1)		(46.0)	1,448.4		(311.5)
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Asset Impairment Charges		(0.6)	(1.1)		(4.1)	(3.3)		(64.7)
Amortization of acquired intangible assets			0.0			(41.8)		(52.8)
Restructuring and transformation expenses(4)		(5.3)	(6.2)		(20.7)	(38.9)		(98.9)
Operating profit (loss)		0.5	36.9		5.5	(5.5)		(169.4)
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating profit (loss)		44.4	90.6		114.2	297.8		299.4
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Operating profit (loss)		44.4	90.6		114.2	297.8		299.4
Corporate
Segment Reporting Information [Line Items]
Operating profit (loss)		26.3	47.0		54.2	(159.8)	[1]	(188.0)	[1]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Operating profit (loss)		26.3	47.0		54.2	(159.8)	[1]	(188.0)	[1]
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Operating profit (loss)		(1.3)	(1.0)		(5.0)	(7.9)		(16.7)
Impairment of assets		(0.6)	(1.1)		4.1	3.3		64.7
Amortization of Wincor Nixdorf purchase accounting intangible assets		(6.1)	0.0		16.6	41.8		52.8
Severance accrual	$ 5.3	4.8	5.1	$ 6.2	20.7	38.4		98.9
Restructuring and Related Cost, Incurred Cost		(0.1)	0.3		(13.4)	(44.7)		(13.4)
Non Routine Expenses Net		4.7	(0.2)		(5.3)	7.4		34.3
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Asset Impairment Charges		0.6	1.1		(4.1)	(3.3)		(64.7)
Amortization of acquired intangible assets		6.1	0.0		(16.6)	(41.8)		(52.8)
Restructuring and transformation expenses(4)	$ (5.3)	(4.8)	(5.1)	$ (6.2)	(20.7)	(38.4)		(98.9)
Restructuring and Related Cost, Incurred Cost		(0.1)	0.3		(13.4)	(44.7)		(13.4)
Net non-routine expense(6)		(4.7)	0.2		5.3	(7.4)		(34.3)
Operating profit (loss)		(1.3)	(1.0)		(5.0)	(7.9)		(16.7)
Corporate and Reconciling Items [Member]
Segment Reporting Information [Line Items]
Reconciliation Of Operating Profit Loss From Segments To Consolidated, Amount		(43.9)	(53.7)		(108.7)	(303.3)		(468.8)
Retail Segment [Member]
Segment Reporting Information [Line Items]
Revenues		(97.2)	(181.1)		(225.0)	(610.0)		(742.4)
Retail Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues		(97.2)	(181.1)		(225.0)	(610.0)		(742.4)
Operating profit (loss)		15.1	31.3		31.1	86.2		90.0
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Operating profit (loss)		15.1	31.3		31.1	86.2		90.0
Other Segments
Segment Reporting Information [Line Items]
Revenues		(1.2)	(1.7)		(5.1)	(10.9)		(16.2)
Global Banking
Segment Reporting Information [Line Items]
Revenues		(253.2)	(409.0)		(580.3)	(1,511.0)		(1,733.3)
Global Banking | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues		(253.2)	(409.0)		(580.3)	(1,511.0)		(1,733.3)
Operating profit (loss)		29.3	59.3		83.1	211.6		209.4
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Operating profit (loss)		29.3	59.3		83.1	211.6		209.4
Service [Member]
Segment Reporting Information [Line Items]
Revenues		(240.6)	(305.5)		(514.3)	(1,295.0)		(1,565.9)
Service [Member] | Retail Segment [Member]
Segment Reporting Information [Line Items]
Revenues		(66.7)	(76.0)		(130.4)	(335.2)		(405.6)
Service [Member] | Other Segments
Segment Reporting Information [Line Items]
Revenues		(0.9)	(1.1)		(4.0)	(5.5)		(7.4)
Service [Member] | Global Banking
Segment Reporting Information [Line Items]
Revenues		(173.0)	(228.4)		(379.9)	(954.3)		(1,152.9)
Product
Segment Reporting Information [Line Items]
Revenues		(111.0)	(286.3)		(296.1)	(836.9)		(926.0)
Product | Retail Segment [Member]
Segment Reporting Information [Line Items]
Revenues		(30.5)	(105.1)		(94.6)	(274.8)		(336.8)
Product | Other Segments
Segment Reporting Information [Line Items]
Revenues		(0.3)	(0.6)		(1.1)	(5.4)		(8.8)
Product | Global Banking
Segment Reporting Information [Line Items]
Revenues		$ (80.2)	$ (180.6)		$ (200.4)	$ (556.7)		$ (580.4)

[1] Corporate charges not allocated to segments include headquarter-based costs associated primarily with human resources, finance, IT and legal that are not directly attributable to a particular segment and are separately assessed by the CODM for purposes of making decisions, assessing performance and allocating resources. It also includes the impact of $2.8 of revenue reversed due to a legal settlement penalty during the Successor Period. (2)    Impairment in the 2023 Successor Period primarily relates to German and Indian facilities. Impairment in the 2023 Predecessor Periods primarily relate to leased European facilities closures. Impairment during the nine months ended September 30, 2022 Predecessor Period was primarily comprised of $38.4 related to impairment of capitalized cloud-based North America ERP, and the Company impaired $16.8 of assets connected with the Company's operations in Russia, Ukraine and Belarus as a result of the Russian incursion into Ukraine and the related economic sanctions. (3)    The amortization of purchase accounting intangible assets is not included in the segment results used by the CODM to make decisions, allocate resources or assess performance. (4)    Refer to Note 11 for further information regarding restructurings. Consistent with the historical reportable segment structure, restructuring and transformation costs are not assigned to the segments, and are separately analyzed by the CODM. (5)    Refinancing related costs are fees earned by our advisors that have been accounted for as period expense. (6)    Net non-routine expense consists of items that the Company has determined are non-routine in nature and not allocated to the reportable operating segments as they are not included in the measure used by the CODM to make decisions, allocate resources and assess performance. (7)    Held for sale non-core European retail business represents the revenue and operating profit of a business that had been classified as held for sale in the Predecessor Period and sold during the Successor Period (see Note 15). It was removed in 2022 from the retail segment's information used by the CODM to make decisions, assess performance and allocate resources, and now is individually analyzed. This change and timing thereof aligns with the build-out of a data center that makes the entity capable of operating autonomously and is consistent with material provided in connection with our refinancing effort which are exclusive of this entity. (8)    Excludes $2.8 of revenue reversed due to a legal settlement penalty during the Successor period.