Investments - Additional Information (Detail) - USD ($) |
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
Jul. 30, 2016 |
Apr. 30, 2016 |
Aug. 01, 2015 |
Jul. 30, 2016 |
Aug. 01, 2015 |
|
| Gain (Loss) on Investments [Line Items] | |||||
| Impairment loss | $ 0 | ||||
| Proceeds from sales of available for sale securities | $ 272,271,000 | 339,837,000 | $ 301,896,000 | ||
| Available for sale securities, net realized gain | $ 261,000 | $ 25,000 | 425,000 | $ 361,000 | |
| Long-term investments | |||||
| Gain (Loss) on Investments [Line Items] | |||||
| Auction rate securities, aggregate par value | 10,000,000 | 10,000,000 | |||
| Long-term investments | Auction rate securities | |||||
| Gain (Loss) on Investments [Line Items] | |||||
| Available for sale securities, sold at par value | 2,500,000 | ||||
| Proceeds from sales of available for sale securities | 2,400,000 | ||||
| Carrying value of available for sale securities after previous written down | $ 2,300,000 | 2,300,000 | |||
| Available for sale securities, net realized gain | $ 100,000 | ||||