Consolidated Statements of Income (Unaudited) (Parenthetical) - $ / shares	3 Months Ended	9 Months Ended
Sep. 28, 2018	Sep. 29, 2017	Sep. 28, 2018	Sep. 29, 2017
Income Statement [Abstract]
Limited partnership interest value	$ 1,000	$ 1,000	$ 1,000	$ 1,000

The per unit price of limited partnership interest, which represents the book value of each interest and has been arbitrarily determined.

No definition available.

Name:	ck0000815917_LimitedPartnershipInterestValuePerUnit
Namespace Prefix:	ck0000815917_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration