Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Oct. 30, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	ST JOE CO
Trading Symbol	JOE
Entity Central Index Key	0000745308
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Current Reporting Status	Yes
Entity Common Stock, Shares Outstanding (in shares)		66,321,224