Name:	cenn_NoticePeriodForSaleOfPartnershipInterest
Namespace Prefix:	cenn_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Number of equity investments which are purchasing of partnership shares and participating shares.

No definition available.

Name:	cenn_NumberOfEquityInvestments
Namespace Prefix:	cenn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

Number of redeemable, non-voting participating shares purchased.

No definition available.

Name:	cenn_NumberOfParticipatingSharesPurchased
Namespace Prefix:	cenn_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

Percentage of fixed return from purchase of partnership shares.

No definition available.

Name:	cenn_PercentageOfIncomeFromInvestmentInEquitySecurities
Namespace Prefix:	cenn_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

The percentage of limited partnership equity securities.

No definition available.

Name:	cenn_PercentageOfLimitedPartnershipEquitySecurities
Namespace Prefix:	cenn_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI), classified as noncurrent.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 45
-Paragraph 1A
-URI https://asc.fasb.org/extlink&oid=123594786&loc=SL75136599-209740

Name:	us-gaap_EquitySecuritiesFVNINoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Cost of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). Excludes equity method investment and investment in equity security without readily determinable fair value.

No definition available.

Name:	us-gaap_EquitySecuritiesFvNiCost
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount of realized gain (loss) from sale of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 321
-SubTopic 10
-Section 50
-Paragraph 4
-URI https://asc.fasb.org/extlink&oid=126980263&loc=SL75117546-209714

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(3)(d))
-URI https://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

Name:	us-gaap_EquitySecuritiesFvNiRealizedGainLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- References

No definition available.

Name:	us-gaap_InvestmentIncomeNetAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The cash outflow for securities or other assets acquired, which qualify for treatment as an investing activity and are to be liquidated, if necessary, beyond the current operating cycle. Includes cash flows from securities classified as trading securities that were acquired for reasons other than sale in the long-term.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3213-108585