XML 50 R26.htm IDEA: XBRL DOCUMENT
v3.24.1

Equity (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2023
Schedule of outstanding, reserved and authorized shares under share-based compensation plans | ​
​ | ​ | ​ | ​ | ​
​ | ​ | December 31, | ​ | December 31,
(in thousands) |  | 2023 |  | 2022
Outstanding options and restricted stock units |  | 3,430 |  | 3,202
Reserved but unissued shares under the Plan | ​ | 2,302 | ​ | 2,777
Total authorized shares under the Plan |  | 5,732 |  | 5,979
Schedule of stock option activity | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | December 31,
​ | ​ | 2023
(in thousands, except per share data) | ​ | Options to Purchase Common Stock | ​ | Weighted Average Exercise Price | ​ | Weighted Average Remaining Contractual Life (in years)
Outstanding at beginning of year |  | 2,779 | ​ | $ | 2.05 |  | 6.43
Granted |  | — | ​ | $ | — |  | —
Exercised |  | (20) | ​ | $ | 0.54 |  | —
Forfeited/Expired |  | — | ​ | $ | — |  | —
Outstanding at end of period |  | 2,759 | ​ | $ | 2.07 |  | 5.38
Exercisable at end of period |  | 2,024 | ​ | $ | 1.71 |  | 4.87
Schedule of restricted stock unit activity | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | December 31, | ​ | December 31,
​ | ​ | 2023 | ​ | 2022
(in thousands, except per share data) | ​ | Number of Shares | ​ | Weighted Average Grant Date Fair Value | ​ | Number of Shares | ​ | Weighted Average Grant Date Fair Value
Nonvested at beginning of year |  | 423 | ​ | $ | 1.49 | ​ | 112 | ​ | $ | 2.28
Granted |  | 617 | ​ | $ | 0.82 | ​ | 376 | ​ | $ | 1.30
Vested |  | (361) | ​ | $ | 1.18 | ​ | (65) | ​ | $ | 1.77
Forfeited | ​ | (8) | ​ | $ | 0.79 | ​ | — | ​ | $ | —
Nonvested at end of period |  | 671 | ​ | $ | 1.05 | ​ | 423 | ​ | $ | 1.49
Schedule of share-based compensation activity | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | ​ | December 31,
(in thousands) |  |  | 2023 |  | 2022
Reserved but unissued shares at beginning of year | ​ | ​ | ​ | 196 | ​ | ​ | 211
Increases in the number of authorized shares | ​ | ​ |  | 7 | ​ |  | —
Grants | ​ | ​ |  | (15) | ​ |  | (15)
Reserved but unissued shares at end of year | ​ | ​ |  | 188 | ​ |  | 196
Restricted Stock Units |
Schedule of compensation expense | ​
​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | For the Year Ended
​ | ​ | December 31,
(in thousands, except per share data) | ​ | 2023 |  | 2022
Compensation Expense | ​ | $ | 337 | $ | 252 | ​
Weighted Average Value Per Share | ​ | $ | 0.83 | $ | 1.57 | ​
Equity Incentive Plan |
Schedule of compensation expense | ​
​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | For the Year Ended
​ | ​ | December 31,
(in thousands, except per share data) |  | 2023 |  | 2022
Fair value | ​ | $ | 234 | ​ | $ | 98
Weighted Average Value Per Share | ​ | $ | 0.79 | ​ | $ | 1.43
Consultant Stock Plan |
Schedule of compensation expense | ​
​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | For the Year Ended
​ | ​ | December 31,
(in thousands, except per share data) |  | 2023 |  | 2022
Compensation Expense | ​ | $ | 10 | ​ | $ | 26
Weighted Average Value Per Share | ​ | $ | 0.69 | ​ | $ | 1.61
​

X
- Definition Tabular disclosure of share-based payment arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 1 -SubTopic 10 -Topic 718 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480429/718-10-50-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480429/718-10-50-2 + Details
Name: | us-gaap_DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of cost recognized for award under share-based payment arrangement by plan. Includes, but is not limited to, related tax benefit. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480429/718-10-50-2 + Details
Name: | us-gaap_ScheduleOfCompensationCostForShareBasedPaymentArrangementsAllocationOfShareBasedCompensationCostsByPlanTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of activity for award under share-based payment arrangement. Includes, but is not limited to, outstanding award at beginning and end of year, granted, exercised, forfeited, and weighted-average grant date fair value. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480429/718-10-50-2 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (d) -SubTopic 10 -Topic 718 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480429/718-10-50-2 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (e) -SubTopic 10 -Topic 718 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480429/718-10-50-2 + Details
Name: | us-gaap_ScheduleOfShareBasedCompensationActivityTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the number and weighted-average grant date fair value for restricted stock units that were outstanding at the beginning and end of the year, and the number of restricted stock units that were granted, vested, or forfeited during the year. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480429/718-10-50-2 + Details
Name: | us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure for stock option plans. Includes, but is not limited to, outstanding awards at beginning and end of year, grants, exercises, forfeitures, and weighted-average grant date fair value. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480429/718-10-50-2 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (d) -SubTopic 10 -Topic 718 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480429/718-10-50-2 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (e) -SubTopic 10 -Topic 718 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480429/718-10-50-2 + Details
Name: | us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_RestrictedStockUnitsRSUMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PlanNameAxis=clir_EquityIncentivePlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PlanNameAxis=clir_ConsultantPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |