Summary of Significant Accounting Policies - Fair Value Measurements (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands |
Jan. 28, 2017 |
Jan. 30, 2016 |
|---|---|---|
| Fair Value, Inputs, Level 1 [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Money market funds | $ 177,551 | $ 152,069 |
| Fair Value, Inputs, Level 2 [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Money market funds | 0 | 0 |
| Fair Value, Inputs, Level 3 [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Money market funds | $ 0 | $ 0 |