Shareholders' Equity / Partners' Capital - Class A Common Shares (Details) $ / shares in Units, $ in Thousands			3 Months Ended		12 Months Ended
	Apr. 05, 2018 $ / shares	Oct. 03, 2017 $ / shares	Sep. 30, 2017 USD ($) $ / shares shares	Mar. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2017 USD ($)
Class of Stock [Line Items]
Proceeds from issuance of class A common shares					$ 0	$ 0	$ 694,765
Class A common shares/units
Class of Stock [Line Items]
Stock exchange ratio	1.4275	1.3106
Issuance of class A common shares, net of offering costs (in shares) | shares			13,800,000	14,842,982
Common shares, par value (in dollars per share) | $ / shares	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01
Proceeds from issuance of class A common shares			$ 312,000	$ 336,500
Stock issuance costs			$ 9,200	$ 400	$ 0	$ 0	$ 10,637
Operating Partnership | Class A Units
Class of Stock [Line Items]
Stock exchange ratio					1
American Homes 4 Rent
Class of Stock [Line Items]
General partner ownership interest					85.20%	84.30%
Operating Partnership | Class A Units
Class of Stock [Line Items]
Units outstanding (in shares) | shares					352,769,654	351,966,447