XML 59 R36.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Pension Plans (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2024
Pension Plans [Abstract] |
Schedule of Information Related to the Retirement Plan | Information related to the Retirement Plan as of and for the years ended December 31, 2024 and 2023 is presented below (dollars in thousands):
|  | 2024 |  |  | 2023 |
Changes in plan assets: |  |  |  |  |  |
Fair value of plan assets, beginning |  | $ | 18,485 |  |  | $ | 16,688 |
Actual gains |  |  | 1,711 |  |  |  | 2,376 |
Benefits paid |  |  | (829 | ) |  |  | (834 | )
Company contributions |  |  | 800 |  |  |  | 255 |
Participant contributions |  |  | — |  |  |  | — |
Fair value of plan assets, ending |  | $ | 20,167 |  |  | $ | 18,485 |
Less: projected accumulated benefit obligation |  | $ | 17,530 |  |  | $ | 18,590 |
Funded status, overfunded (underfunded) |  | $ | 2,637 |  |  | $ | (105 | )
Amounts recognized in the consolidated balance sheets: |  |  |  |  |  |  |  |
Other assets |  | $ | 2,637 |  |  | $ | — |
Other liabilities |  | $ | — |  |  | $ | (105 | )
Accumulated other comprehensive income |  | $ | (4,167 | ) |  | $ | (2,231 | )
Assumptions used in computation of benefit obligations: |  |  |  |  |  |  |  |
Discount rate |  |  | 5.50 | % |  |  | 4.90 | %
Expected long-term return on plan assets |  |  | 6.50 | % |  |  | 6.50 | %
Rate of compensation increase |  |  | — |  |  |  | — |
Schedule of Components of Net Periodic Benefit Costs |
|  | Years Ended December 31, |
|  | 2024 |  |  | 2023 |  |  | 2022 |
Components of net periodic benefit costs are as follows: |  |  |  |  |  |  |  |  |
Service cost |  | $ | 267 |  |  | $ | 249 |  |  | $ | 404 |
Interest cost |  |  | 887 |  |  |  | 900 |  |  |  | 655 |
Expected return on plan assets |  |  | (1,103 | ) |  |  | (993 | ) |  |  | (1,090 | )
Net periodic cost (benefit) |  | $ | 51 |  |  | $ | 156 |  |  | $ | (31 | )
Schedule of Expected Benefit Payments | The following table summarizes the expected benefit payments for the Company’s Retirement Plan for each of the next five fiscal years and in the aggregate for the five fiscal years thereafter (in thousands):
December 31: |  |  |
2025 |  | $ | 1,000 |
2026 |  |  | 1,040 |
2027 |  |  | 1,080 |
2028 |  |  | 1,130 |
2029 |  |  | 1,160 |
2030-34 |  |  | 6,480 |
|  | $ | 11,890 |
Schedule of Information Related to the Postretirement Plan | Information related to the Postretirement Plan as of December 31, 2024 and 2023 is presented below (dollars in thousands):
|  | 2024 |  |  | 2023 |
Amounts at the end of the year: |  |  |  |  |  |
Accumulated/projected benefit obligation |  | $ | 3,783 |  |  | $ | 4,294 |
Fair value of plan assets |  |  | — |  |  |  | — |
Funded status, underfunded |  | $ | (3,783 | ) |  | $ | (4,294 | )
Amounts recognized in the consolidated balance sheets: |  |  |  |  |  |  |  |
Accrued liabilities |  | $ | (280 | ) |  | $ | (320 | )
Other liabilities |  | $ | (3,503 | ) |  | $ | (3,974 | )
Accumulated other comprehensive income |  | $ | (808 | ) |  | $ | (250 | )
Discount rate used in computation of benefit obligations |  |  | 5.30 | % |  |  | 4.75 | %
Schedule of Net Periodic Benefit Costs |
|  | Years Ended December 31, |
|  | 2024 |  |  | 2023 |  |  | 2022 |
Components of net periodic benefit costs are as follows: |  |  |  |  |  |  |  |  |
Service cost |  | $ | 19 |  |  | $ | 14 |  |  | $ | 26 |
Interest cost |  |  | 196 |  |  |  | 186 |  |  |  | 105 |
Amortization of prior service cost |  |  | — |  |  |  | (53 | ) |  |  | — |
Net periodic benefit cost |  | $ | 215 |  |  | $ | 147 |  |  | $ | 131 |
Amounts recognized in the plan for the year: |  |  |  |  |  |  |  |  |  |  |  |
Participant contributions |  | $ | 35 |  |  | $ | 36 |  |  | $ | 43 |
Benefits paid |  | $ | 204 |  |  | $ | 201 |  |  | $ | 215 |
Schedule of Expected Benefit Payments | The following table summarizes the expected benefit payments for the Company’s Postretirement Plan for each of the next five fiscal years and in the aggregate for the five fiscal years thereafter (in thousands):
December 31: |  |  |
2025 |  | $ | 280 |
2026 |  |  | 360 |
2027 |  |  | 390 |
2028 |  |  | 420 |
2029 |  |  | 400 |
2030-2034 |  |  | 1,780 |
|  | $ | 3,630 |

X
- Definition Tabular disclosure of expected post retirement benefit payments. + References No definition available. + Details
Name: | alto_ScheduleOfExpectedPostRetirementBenefitPaymentsTableTextBlock
Namespace Prefix: | alto_
Data Type: | dtr:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_PensionAndOtherPostretirementAndPostemploymentBenefitPlansNoncurrentLiabilitiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the costs related to the various types of retirement plans including defined benefit pension plan cost, defined contribution plan cost, other postretirement benefit plan cost, and net periodic benefit cost. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 1 -SubTopic 20 -Topic 715 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 + Details
Name: | us-gaap_ScheduleOfCostsOfRetirementPlansTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of one or more of the entity's defined benefit pension plans or one or more other defined benefit postretirement plans, separately for pension plans and other postretirement benefit plans including the entity's schedule of fair value of plan assets for defined benefit or other postretirement plans. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 1 -SubTopic 20 -Topic 715 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 17 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480482/715-20-55-17 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-3 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-4 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-2 + Details
Name: | us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of benefits expected to be paid by pension plans and/or other employee benefit plans in each of the next five fiscal years and in the aggregate for the five fiscal years thereafter. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 715 -SubTopic 20 -Subparagraph (f) -Name Accounting Standards Codification -Paragraph 1 -Section 50 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 + Details
Name: | us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the components of net benefit costs for pension plans and/or other employee benefit plans including service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) recognized due to settlements or curtailments. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 715 -SubTopic 20 -Subparagraph (h) -Name Accounting Standards Codification -Paragraph 1 -Section 50 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 + Details
Name: | us-gaap_ScheduleOfNetBenefitCostsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the amounts related to pension plans and/or other employee benefit plans in accumulated other comprehensive income or loss that have not yet been recognized as components of net periodic benefit cost, such as the net gain (loss), net prior service cost or credit, and net transition asset or obligation. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 715 -SubTopic 20 -Subparagraph (j) -Name Accounting Standards Codification -Paragraph 1 -Section 50 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 + Details
Name: | us-gaap_ScheduleOfNetPeriodicBenefitCostNotYetRecognizedTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration