XML 92 R81.htm IDEA: XBRL DOCUMENT
v3.25.3

Restructuring - Additional Information (Details) - USD ($) $ in Millions |  |  | 9 Months Ended |  |
--- | --- | --- | --- | --- | ---
May 06, 2025 | Feb. 20, 2023 | Sep. 30, 2025 | Mar. 31, 2025 | Dec. 31, 2024
Restructuring Cost And Reserve [Line Items] |  |  |  |  |
Total expenses |  |  | $ 180 |  |
Expected cumulative costs |  |  | 205 |  |
Accounts Payable and Accrued Liabilites |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |
Accrued restructuring liability |  |  | 18 |  |
Severance Charges |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |
Accrued restructuring liability |  |  | $ 18 |  | $ 12
Two-Year Strategic Transformation Restructuring Program |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |
Restructuring activities estimated completion period |  | 2 years |  |  |
The Plan |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |
Total expenses |  |  |  | $ 140 |
Post-Separation Plan |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |
Restructuring activities estimated completion period |  |  | 15 months |  |
Total expenses |  |  | $ 40 |  |
Expected cumulative costs | $ 65 |  | 65 |  |
Restructuring activities estimated annual savings | 75 |  |  |  |
Post-Separation Plan | Severance Charges |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |
Total expenses |  |  | 20 |  |
Expected cumulative costs | 20 |  | 20 |  |
Accrued restructuring liability |  |  | 14 |  | $ 0
Post-Separation Plan | Other Restructuring Charges |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |
Total expenses |  |  | 20 |  |
Expected cumulative costs |  |  | $ 45 |  |
Post-Separation Plan | Other Restructuring Charges | Minimum |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |
Expected cumulative costs | 35 |  |  |  |
Post-Separation Plan | Other Restructuring Charges | Maximum |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |
Expected cumulative costs | $ 45 |  |  |  |

X
- Definition Restructuring and related activities estimated annual savings. + References No definition available. + Details
Name: | alit_RestructuringAndRelatedActivitiesEstimatedAnnualSavings
Namespace Prefix: | alit_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Restructuring and related activities estimated completion period. + References No definition available. + Details
Name: | alit_RestructuringAndRelatedActivitiesEstimatedCompletionPeriod
Namespace Prefix: | alit_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of costs incurred to date for the specified restructuring cost. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 420 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SAB Topic 5.P.4.d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479823/420-10-S99-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 420 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SAB Topic 5.P.4.b.1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479823/420-10-S99-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 420 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482017/420-10-50-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 420 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482017/420-10-50-1 + Details
Name: | us-gaap_RestructuringAndRelatedCostCostIncurredToDate1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount expected to be recognized in earnings for the specified restructuring cost. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 420 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SAB Topic 5.P.4.d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479823/420-10-S99-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 420 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SAB Topic 5.P.4.b.1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479823/420-10-S99-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 420 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482017/420-10-50-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 420 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482017/420-10-50-1 + Details
Name: | us-gaap_RestructuringAndRelatedCostExpectedCost1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 420 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SAB Topic 5.P.4.d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479823/420-10-S99-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 420 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SAB Topic 5.P.4.b.1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479823/420-10-S99-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 420 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SAB Topic 5.P.4.b.2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479823/420-10-S99-2 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 420 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482017/420-10-50-1 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 420 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482017/420-10-50-1 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 420 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482017/420-10-50-1 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 420 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482017/420-10-50-1 + Details
Name: | us-gaap_RestructuringCostAndReserveLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 420 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SAB Topic 5.P.4.b.2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479823/420-10-S99-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 420 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482017/420-10-50-1 + Details
Name: | us-gaap_RestructuringReserve
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_AccountsPayableAndAccruedLiabilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RestructuringCostAndReserveAxis=us-gaap_EmployeeSeveranceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RestructuringPlanAxis=alit_TwoYearStrategicTransformationRestructuringProgramMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RestructuringPlanAxis=alit_ManagementInitiatedRestructuringAndIntegrationPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RestructuringPlanAxis=alit_PostSeparationPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RestructuringCostAndReserveAxis=us-gaap_OtherRestructuringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |