Document and Entity Information - shares	6 Months Ended
	Jun. 28, 2019	Jul. 26, 2019
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 28, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Trading Symbol	N/A
Entity Registrant Name	JONES FINANCIAL COMPANIES LLLP
Entity Central Index Key	0000815917
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Limited Partnership Interests Outstanding		1,256,036
Entity File Number	0-16633
Entity Tax Identification Number	431450818
Entity Address, Address Line One	12555 Manchester Road
Entity Address, City or Town	Des Peres
Entity Address, State or Province	Missouri
Entity Address, Postal Zip Code	63131
City Area Code	314
Local Phone Number	515-2000