Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Feb. 24, 2020	Jun. 30, 2019
Document and Entity Information [Abstract]
Document Type	10-K
Document Period End Date	Dec. 31, 2019
Entity Registrant Name	ST JOE CO
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 349.7
Entity Common Stock, Shares Outstanding		59,414,583
Entity Central Index Key	0000745308
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Amendment Flag	false