Fair Value Measurements - Amortized Cost and Fair Market Value of Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Jan. 28, 2017	Jan. 30, 2016	Jan. 31, 2015
Amortized Cost
Mature in one year or less	$ 38,026	$ 32,671
Mature after one year through five years	26,691	30,890
Total	64,717	63,561
Fair Market Value
Mature in one year or less	38,028	32,675
Mature after one year through five years	26,640	30,916
Total Fair Market Value	64,668	63,591
Changes among the fair value levels
Changes between Level 1 to Level 2, Assets	0	0	$ 0
Changes between Level 2 to Level 1, Assets	$ 0	$ 0	$ 0

Amount of transfers of assets measured on a recurring basis out of Level 1 of the fair value hierarchy into Level 2.

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Amount of transfers of assets measured on a recurring basis out of Level 2 of the fair value hierarchy into Level 1.

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Amount after other than temporary impairment (OTTI) accretion, of investments in debt securities classified as held-to-maturity.

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Fair value of held-to-maturity debt securities maturing in the second fiscal year through the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Carrying amount of debt securities accounted for as held-to-maturity, net of adjustments including, but not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized, and fair value hedge accounting adjustments, maturing in the next fiscal year through the fifth fiscal year following the latest fiscal year.

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Fair value of held-to-maturity debt securities maturing in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Fair value of investments in debt securities classified as held-to-maturity.

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