Debt - Additional Information (Details) - USD ($)		1 Months Ended			3 Months Ended		6 Months Ended
Debt - Additional Information (Details) - USD ($)	Jun. 27, 2025	Jun. 30, 2025	Jun. 27, 2025	Jun. 27, 2025	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Jun. 11, 2025	Dec. 31, 2024
Debt Instrument [Line Items]
Payment of aggregate principal amount							$ 488,600,000	$ 10,100,000
Loss on debt extinguishment					$ 6,800,000	$ 0	6,800,000	$ 0
10.625% senior secured notes due January 15, 2031 \| Senior Notes
Debt Instrument [Line Items]
Aggregate principal amount		$ 700,000,000.0			$ 700,000,000.0		$ 700,000,000.0
Convertible senior notes interest rate		10.625%			10.625%		10.625%
Senior secured notes		$ 685,900,000			$ 685,900,000		$ 685,900,000			$ 0
10.625% senior secured notes due January 15, 2031 \| Senior Notes \| Debt Instrument, Redemption, Period One
Debt Instrument [Line Items]
Redemption price, proportion of principal amount (in percent)		100.00%
10.625% senior secured notes due January 15, 2031 \| Senior Notes \| Debt Instrument, Redemption, Period Two
Debt Instrument [Line Items]
Principal amount redeemed percentage		40.00%
10.625% senior secured notes due January 15, 2031 \| Senior Notes \| Debt Instrument, Redemption, Period Three
Debt Instrument [Line Items]
Redemption price, proportion of principal amount (in percent)		110.625%
10.625% senior secured notes due January 15, 2031 \| Senior Notes \| Debt Instrument, Redemption, Period Four
Debt Instrument [Line Items]
Principal amount redeemed percentage		10.00%
10.625% senior secured notes due January 15, 2031 \| Senior Notes \| Debt Instrument, Redemption, Period Five
Debt Instrument [Line Items]
Redemption price, proportion of principal amount (in percent)		103.00%
10.625% senior secured notes due January 15, 2031 \| Senior Notes \| Debt Instrument, Redemption, Period Six
Debt Instrument [Line Items]
Redemption price, proportion of principal amount (in percent)							101.00%
6.875% senior secured notes due November 1, 2027 \| Senior Notes
Debt Instrument [Line Items]
Aggregate principal amount		$ 485,000,000.0			$ 485,000,000.0		$ 485,000,000.0			485,000,000
Convertible senior notes interest rate		6.875%			6.875%		6.875%
Tender offer price									$ 1,006.25
Tender offer, premium price									$ 30.00
Payment of aggregate principal amount			$ 488,600,000
Premium amount	$ 3,000,000		3,000,000	$ 3,000,000
Accrued interest				5,500,000
Repayment of aggregate principal amount				480,100,000
Senior secured notes	4,900,000	$ 0	$ 4,900,000	$ 4,900,000	$ 0		$ 0			$ 481,600,000
Loss on debt extinguishment	6,800,000
Write-off of unamortized debt issuance costs	$ 3,800,000
Amended and Restated ABL Credit Facility \| Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity		125,000,000			125,000,000		125,000,000
Accordion feature increase limit up to		155,000,000			155,000,000		155,000,000
Borrowings outstanding		0			0		0
Availability under the facility, net of letters of credit issued		99,100,000			99,100,000		$ 99,100,000
Springing maturity, period prior to any date on which domestic pension contributions in an amount in excess of threshold are required to be paid							91 days
Springing maturity, date on which pension contributions to pension funds in the United States are required to be paid, threshold excess amount							$ 100,000,000
Springing maturity, conditions, minimum liquidity							130,000,000
Amended and Restated ABL Credit Facility \| Letter of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity		40,000,000			40,000,000		40,000,000
Letters of credit outstanding		$ 8,300,000			$ 8,300,000		$ 8,300,000
Amended and Restated ABL Credit Facility \| Line of Credit \| Revolving Credit Facility
Debt Instrument [Line Items]
Requirement to maintain minimum fixed charge coverage ratio (in percent)		10.00%			10.00%		10.00%
Requirement to maintain minimum fixed charge coverage ratio, availability threshold		$ 12,500,000			$ 12,500,000		$ 12,500,000
Amount of aggregate default under other debt that would trigger event of default at least		$ 50,000,000.0			$ 50,000,000.0		$ 50,000,000.0

UNISYS CORP 10-Q