Fixed Assets - Minimum future payments (Details)	Dec. 31, 2020 USD ($)
Payments Due Under Lease Agreement [Member]
2021	$ 193,000
2022	190,000
2023	72,000
Total	455,000
Discounted Lease Liabilities Payments [Member].
2021	169,000
2022	178,000
2023	71,000
Total	$ 418,000

Amount of lessee's discounted obligation for lease payments for operating lease.

No definition available.

Name:	clir_LesseeOperatingLeaseLiabilityDiscountedPaymentsDue
Namespace Prefix:	clir_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of lessee's discounted obligation for lease payments for operating lease, due in next fiscal year following latest fiscal year.

+ References

No definition available.

+ Details

Name:	clir_LesseeOperatingLeaseLiabilityDiscountedPaymentsDueNextTwelveMonths
Namespace Prefix:	clir_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of lessee's discounted obligation for lease payments for operating lease, due in third fiscal year following latest fiscal year.

+ References

No definition available.

+ Details

Name:	clir_LesseeOperatingLeaseLiabilityDiscountedPaymentsDueYearThree
Namespace Prefix:	clir_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of lessee's discounted obligation for lease payments for operating lease, due in second fiscal year following latest fiscal year.

+ References

No definition available.

+ Details

Name:	clir_LesseeOperatingLeaseLiabilityDiscountedPaymentsDueYearTwo
Namespace Prefix:	clir_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of lessee's undiscounted obligation for lease payment for operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=121609121&loc=SL77918701-209980

+ Details

Name:	us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

+ Details

Name:	us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

+ Details

Name:	us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

+ Details

Name:	us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_LeaseContractualTermAxis=clir_PaymentsDueUnderLeaseAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LeaseContractualTermAxis=clir_DiscountedLeaseLiabilitiesPaymentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: