Accumulated Other Comprehensive Income (Tables)

6 Months Ended

Jun. 27, 2015

Accumulated Other Comprehensive Income [Abstract]

Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]

		Unrealized Gains
		on Available-for-Sale
(dollars in thousands)		Marketable Securities
Accumulated other comprehensive income balance as of December 27, 2014	$	4,829
Other comprehensive loss before reclassifications		(109)
Amounts reclassified from accumulated other comprehensive income		(8)
Net current period other comprehensive loss		(117)
Accumulated other comprehensive income balance as of June 27, 2015	$	4,712

Reclassification out of Accumulated Other Comprehensive Income [Table Text Block]

		Gains (Losses) Reclassified from
		Accumulated Other Comprehensive Income to the
		Consolidated Statements of Income
		13 Weeks Ended				26 Weeks Ended
(dollars in thousands)	Location		June 27, 2015		June 28, 2014		June 27, 2015		June 28, 2014
Unrealized gains on available-for-sale marketable securities
	Investment income	$	9	$	5	$	15	$	46
	Provision for income taxes		(4)		(2)		(7)		(20)
Total amount reclassified, net of tax		$	5	$	3	$	8	$	26