Changes in Accumulated Other Comprehensive Income (Details) - USD ($)	3 Months Ended		6 Months Ended
	Aug. 04, 2018	Jul. 29, 2017	Aug. 04, 2018	Jul. 29, 2017
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance Accumulated other comprehensive income, net of tax			$ (321,000)
Unrealized gain on available-for-sale securities, net of deferred income taxes	$ 314,000	$ 192,000	(78,000)	$ 625,000
Ending Balance Accumulated other comprehensive income, net of tax	(399,000)		(399,000)
ChangeInUnrealizedGainsOnAvailableForSaleSecuritiesMember [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance Accumulated other comprehensive income, net of tax	(713,000)	219,000	(321,000)	(214,000)
Other Comprehensive Income Loss Before Reclassifications Net Of Tax	260,000	186,000	(131,000)	622,000
Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax	54,000	6,000	53,000	3,000
Unrealized gain on available-for-sale securities, net of deferred income taxes	314,000	192,000	(78,000)	625,000
Ending Balance Accumulated other comprehensive income, net of tax	$ (399,000)	$ 411,000	$ (399,000)	$ 411,000