Note 11 (Details Textual)	3 Months Ended		6 Months Ended
	Mar. 26, 2016 USD ($)	Mar. 28, 2015 USD ($)	Mar. 26, 2016 USD ($)	Mar. 28, 2015 USD ($)	Sep. 26, 2015 USD ($)
Four Mutual Funds [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	$ 1,200,000		$ 1,200,000
Number of Funds			4
Marketable Securities	13,900,000		$ 13,900,000
Preferred Stock [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	748,000		748,000		$ 163,000
Marketable Securities	19,700,000		$ 19,700,000
Number of Holdings			16
Classification of Noncurrent Asset, Fixed-to-Floating Perpetual Preferred Stock			1 year
Mutual Funds [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	1,240,000		$ 1,240,000		827,000
Classification Of Noncurrent Asset, Mutual Funds, Period			1 year
Corporate Bond Securities [Member]
Held-to-maturity Securities	76,000,000		$ 76,000,000
Investment Securities Maturity Term			3 years
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	1,988,000		$ 1,988,000		990,000
Held-to-maturity Securities	96,649,000		96,649,000		$ 66,660,000
Proceeds from Sale and Maturity of Marketable Securities	4,186,000	$ 2,000,000	5,384,000	$ 13,601,000
Marketable Securities, Gain (Loss)	$ 297,000	$ 0	$ 406,000	$ (509,000)