Fair Value Measurement - Amortized Cost and Fair Market Value of Securities by Contractual Maturity (Details) - USD ($) $ in Thousands |
Aug. 04, 2018 |
Feb. 03, 2018 |
|---|---|---|
| Amortized Cost | ||
| Mature in one year or less | $ 36,009 | $ 31,500 |
| Mature after one year through five years | 13,020 | 25,451 |
| Total | 49,029 | 56,951 |
| Fair Market Value | ||
| Mature in one year or less | 35,903 | 31,474 |
| Mature after one year through five years | 12,992 | 25,335 |
| Total Fair Market Value | 48,895 | $ 56,809 |
| Changes among the fair value levels | ||
| Changes between Level 1 to Level 2, Assets | $ 0 |