Summary of Significant Accounting Policies (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended								3 Months Ended		9 Months Ended
	Nov. 30, 2016	Aug. 31, 2016	May 31, 2016	Mar. 31, 2016	Nov. 30, 2015	Aug. 31, 2015	May 31, 2015	Feb. 28, 2015	Oct. 29, 2016	Oct. 31, 2015	Oct. 29, 2016	Oct. 31, 2015	Jan. 30, 2016
Summary of Significant Accounting Policies [Line Items]
Cash dividends declared per share (in dollars per share)		$ 0.135	$ 0.1350	$ 0.135	$ 0.1175	$ 0.1175	$ 0.1175	$ 0.1175	$ 0.135	$ 0.1175	$ 0.405	$ 0.3525
Reclassification into long-term deferred tax liabilities									$ 122,048	$ 70,316	$ 122,048	$ 70,316	$ 130,088
Property, Plant and Equipment [Member]
Summary of Significant Accounting Policies [Line Items]
Property and equipment purchased but not yet paid											$ 7,400	9,200
Accounting Standards Update 2015-17 [Member]
Summary of Significant Accounting Policies [Line Items]
Reclassification out of current deferred tax assets										9,200		9,200
Reclassification into long-term deferred tax liabilities										$ 9,200		$ 9,200
Subsequent Event [Member]
Summary of Significant Accounting Policies [Line Items]
Cash dividends declared per share (in dollars per share)	$ 0.135