Changes in Accumulated Other Comprehensive Income Components - (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Oct. 29, 2016	Oct. 31, 2015	Oct. 29, 2016	Oct. 31, 2015
ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeLineItems
Income Tax Benefit (Expense)	$ (4,886)	$ 1,043	$ 11,513	$ 27,310
Reclassified Accumulated Unrealized Gains and Losses
ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeLineItems
Interest and Other Income	(185)	(32)	(269)	203
Income Tax Benefit (Expense)	$ (69)	$ (12)	$ (101)	$ 76

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a),(b)
-URI http://asc.fasb.org/extlink&oid=65882285&loc=d3e32639-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(h))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Income Tax Expense (or Benefit)
-URI http://asc.fasb.org/extlink&oid=6515339

Name:	us-gaap_IncomeTaxExpenseBenefit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration