Label	Element	Value
Stock Issued During Period, Value, Restricted Stock Award, Gross	us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross	$ 0
Stock Issued During Period Value In Settlement Of Issuing Cost With Parent Entity	cone_StockIssuedDuringPeriodValueInSettlementOfIssuingCostWithParentEntity	0
Stock Issued During Period, Value, New Issues	us-gaap_StockIssuedDuringPeriodValueNewIssues	337,100,000
Noncontrolling Interest, Increase from Business Combination	us-gaap_NoncontrollingInterestIncreaseFromBusinessCombination	0
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	6,200,000
Contributions From Parent	cone_ContributionsFromParent	19,600,000
Other Contribution From Parent	cone_OtherContributionFromParent	1,300,000
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs	us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts	9,500,000
Additional Paid-in Capital [Member]
Stock Issued During Period Value In Settlement Of Issuing Cost With Parent Entity	cone_StockIssuedDuringPeriodValueInSettlementOfIssuingCostWithParentEntity	7,100,000
Stock Issued During Period, Value, New Issues	us-gaap_StockIssuedDuringPeriodValueNewIssues	336,900,000
Noncontrolling Interest, Increase from Business Combination	us-gaap_NoncontrollingInterestIncreaseFromBusinessCombination	(7,100,000)
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	6,200,000
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs	us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts	$ 9,500,000
Common Stock [Member]
Stock Issued During Period, Shares, Restricted Stock Award, Gross	us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross	1,100,000
Stock Issued During Period Share In Settlement Of Issuing Cost With Parent Entity	cone_StockIssuedDuringPeriodShareInSettlementOfIssuingCostWithParentEntity	400,000
Stock Issued During Period, Value, New Issues	us-gaap_StockIssuedDuringPeriodValueNewIssues	$ 200,000
Stock Issued During Period Share To Parent Entity In Exchange Of Equity Interest In Third Entity	cone_StockIssuedDuringPeriodShareToParentEntityInExchangeOfEquityInterestInThirdEntity	1,500,000
Stock Issued During Period, Shares, New Issues	us-gaap_StockIssuedDuringPeriodSharesNewIssues	19,000,000
Noncontrolling Interest [Member]
Stock Issued During Period Value In Settlement Of Issuing Cost With Parent Entity	cone_StockIssuedDuringPeriodValueInSettlementOfIssuingCostWithParentEntity	$ (7,100,000)
Noncontrolling Interest, Increase from Business Combination	us-gaap_NoncontrollingInterestIncreaseFromBusinessCombination	500,800,000
Parent [Member]
Stock Issued During Period Value In Settlement Of Issuing Cost With Parent Entity	cone_StockIssuedDuringPeriodValueInSettlementOfIssuingCostWithParentEntity	7,100,000
Stock Issued During Period, Value, New Issues	us-gaap_StockIssuedDuringPeriodValueNewIssues	337,100,000
Noncontrolling Interest, Increase from Business Combination	us-gaap_NoncontrollingInterestIncreaseFromBusinessCombination	(500,800,000)
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	6,200,000
Contributions From Parent	cone_ContributionsFromParent	19,600,000
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	us-gaap_ProfitLoss	(20,200,000)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	us-gaap_ProfitLoss	(15,600,000)
Other Contribution From Parent	cone_OtherContributionFromParent	1,300,000
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs	us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts	9,500,000
Partnership Interest [Member]
Noncontrolling Interest, Increase from Business Combination	us-gaap_NoncontrollingInterestIncreaseFromBusinessCombination	(493,700,000)
Contributions From Parent	cone_ContributionsFromParent	19,600,000
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	us-gaap_ProfitLoss	(20,200,000)
Other Contribution From Parent	cone_OtherContributionFromParent	1,300,000
Retained Earnings [Member]
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders	13,600,000
Net Income (Loss) Attributable to Noncontrolling Interest	us-gaap_NetIncomeLossAttributableToNoncontrollingInterest	10,300,000
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	us-gaap_ProfitLoss	$ (15,600,000)