Note C - Investment Securities (Details Textual) - USD ($)	12 Months Ended
	Sep. 24, 2016	Sep. 26, 2015	Sep. 27, 2014
Mutual Fund [Member]
Available-for-sale Securities	$ 12,483,000	$ 19,214,000	$ 128,000,000
Unrealized Gain (Loss) on Securities	$ 520,000
Number of Funds	4
Marketable Securities	$ 12,500,000
Marketable Securities, Annual Income, Percentage	4.90%
Preferred Stock [Member]
Available-for-sale Securities	$ 16,982,000	20,424,000
Marketable Securities	$ 17,000,000
Marketable Securities, Annual Income, Percentage	5.50%
Marketable Securities, Annual Income, Percentage, not Subject to Tax	70.00%
Classification of Noncurrent Asset, Fixed-to-Floating Perpetual Preferred Stock	1 year
Corporate Bond Securities [Member]
Marketable Securities	$ 103,000,000
Marketable Securities, Annual Income, Percentage	2.20%
Held-to-maturity Securities, Debt Maturities, without Single Maturity Date, Net Carrying Amount	$ 67,000,000
Available-for-sale Securities	29,465,000	39,638,000
Proceeds from Sale and Maturity of Marketable Securities	13,224,000	110,117,000	7,245,000
Marketable Securities, Gain (Loss)	$ (661,000)	$ (4,319,000)	$ (361,000)