DEI Document (USD $)	12 Months Ended
	Dec. 31, 2012	Apr. 30, 2013
Entity [Abstract]
Entity Registrant Name	CAPITAL REALTY INVESTORS IV LIMITED PARTNERSHIP
Entity Central Index Key	0000740371
Current Fiscal Year End Date	--12-31
Entity Filer Category	Smaller Reporting Company
Document Type	10-K
Document Period End Date	Dec. 31, 2012
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Partnership Units Outstanding		73,337
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float	$ 0