Document and Entity Information - shares
9 Months Ended
Sep. 30, 2019
Nov. 01, 2019
Entity Information [Line Items]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Sep. 30, 2019  
Document Transition Report false  
Entity File Number 001-16441  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 76-0470458  
Entity Address, Address Line One 1220 Augusta Drive  
Entity Address, Address Line Two Suite 600  
Entity Address, City or Town Houston  
Entity Address, State or Province TX  
Entity Address, Postal Zip Code 77057-2261  
City Area Code 713  
Local Phone Number 570-3000  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   415,768,468
Entity Central Index Key 0001051470  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q3  
Amendment Flag false  
Common Stock [Member]    
Entity Information [Line Items]    
Title of 12(b) Security Common Stock, $0.01 par value  
Trading Symbol CCI  
Security Exchange Name NYSE  
6.875% Mandatory Convertible Preferred Stock [Member]    
Entity Information [Line Items]    
Title of 12(b) Security 6.875% Mandatory Convertible Preferred Stock, Series A, $0.01 par value  
Trading Symbol CCI.PRA  
Security Exchange Name NYSE