Document and Entity Information	6 Months Ended
	Jun. 30, 2019 shares
Document And Entity Information [Abstract]
Entity Registrant Name	AMERICA FIRST MULTIFAMILY INVESTORS, L.P.
Entity Central Index Key	0001059142
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Document Type	10-Q
Document Period End Date	Jun. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Amendment Flag	false
Trading Symbol	ATAX
Entity Common Stock, Units Outstanding	60,426,177
Entity Shell Company	false
Entity Current Reporting Status	Yes
Entity File Number	000-24843
Entity Tax Identification Number	470810385
Entity Address, Address Line One	1004 Farnam Street
Entity Address, Address Line Two	Suite 400
Entity Address, City or Town	Omaha
Entity Address, State or Province	Nebraska
Entity Address, Postal Zip Code	68102
City Area Code	(402)
Local Phone Number	444-1630