Fair Value of Financial Instruments (Details) - Fair Value, Measurements, Recurring - USD ($)
$ in Thousands |
Apr. 29, 2017 |
Jan. 28, 2017 |
| Level 1 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Cash equivalents |
$ 904
|
$ 0
|
| Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Cash equivalents |
22,198
|
0
|
| Level 3 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Cash equivalents |
0
|
0
|
| Municipal securities | Level 1 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Short-term investments |
0
|
0
|
| Long-term investments |
0
|
0
|
| Municipal securities | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Short-term investments |
4,533
|
0
|
| Long-term investments |
2,079
|
0
|
| Municipal securities | Level 3 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Short-term investments |
0
|
0
|
| Long-term investments |
0
|
0
|
| Commercial paper | Level 1 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Short-term investments |
0
|
0
|
| Commercial paper | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Short-term investments |
3,491
|
0
|
| Commercial paper | Level 3 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Short-term investments |
0
|
0
|
| U.S. corporate debt securities | Level 1 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Short-term investments |
0
|
0
|
| Long-term investments |
0
|
0
|
| U.S. corporate debt securities | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Short-term investments |
1,465
|
0
|
| Long-term investments |
7,282
|
0
|
| U.S. corporate debt securities | Level 3 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Short-term investments |
0
|
0
|
| Long-term investments |
0
|
0
|
| Certificate of deposit | Level 1 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Short-term investments |
0
|
0
|
| Certificate of deposit | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Short-term investments |
0
|
30,152
|
| Certificate of deposit | Level 3 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Short-term investments |
0
|
0
|
| Non-U.S. corporate debt securities | Level 1 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Long-term investments |
0
|
0
|
| Non-U.S. corporate debt securities | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Long-term investments |
6,144
|
0
|
| Non-U.S. corporate debt securities | Level 3 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Long-term investments |
0
|
0
|
| U.S. treasury securities | Level 1 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Long-term investments |
2,014
|
0
|
| U.S. treasury securities | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Long-term investments |
0
|
0
|
| U.S. treasury securities | Level 3 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Long-term investments |
$ 0
|
$ 0
|