Investments (Schedule of Investments) (Details) - USD ($) $ in Thousands	Oct. 28, 2017	Jan. 28, 2017
Auction-rate securities [Member]
Available-for-sale Securities [Abstract]
Available-for-Sale Securities, Amortized Cost or Par Value	$ 1,725	$ 1,800
Available-for-Sale Securities, Gross Unrealized Gains	0	0
Available-for-Sale Securities, Gross Unrealized Losses	(125)	(130)
Available-for-Sale Securities, Other-than-Temporary Impairment	0	0
Available-for-Sale Securities, Estimated Fair Value	1,600	1,670
State and municipal bonds [Member]
Held-to-maturity Securities [Abstract]
Held-to-Maturity Securities, Amortized Cost or Par Value	54,407	53,324
Held-to-Maturity Securities, Gross Unrealized Gains	4	26
Held-to-Maturity Securities, Gross Unrealized Losses	(40)	(34)
Held-to-Maturity Securities, Other-than-Temporary Impairment	0	0
Held-to-Maturity Securities, Estimated Fair Value	54,371	53,316
Mutual funds [Member]
Trading Securities [Abstract]
Trading Securities, Amortized Cost or Par Value	13,333	12,701
Trading Securities, Gross Unrealized Gains	1,248	391
Trading Securities, Gross Unrealized Losses	0	0
Trading Securities, Other-than-Temporary Impairment	0	0
Trading Securities, Estimated Fair Value	$ 14,581	$ 13,092