Fair Value Measurements - Schedule of Carrying Values and Estimated Fair Values of Long-Term Debt (Detail) - USD ($)
$ in Thousands |
Apr. 30, 2016 |
Jan. 31, 2016 |
Mar. 02, 2015 |
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |
|
|
|
| Convertible notes carrying value |
$ 159,783
|
$ 158,971
|
|
| 4.25% Convertible Notes [Member] | Convertible Senior Notes [Member] |
|
|
|
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |
|
|
|
| Convertible notes carrying value |
62,398
|
61,766
|
|
| Convertible notes fair value |
|
|
$ 42,100
|
| 8.0% Convertible Notes [Member] | Convertible Senior Notes [Member] |
|
|
|
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |
|
|
|
| Convertible notes carrying value |
97,385
|
97,205
|
|
| Fair Value Measurements Nonrecurring | Fair Value Measurements - Level 1 [Member] | 4.25% Convertible Notes [Member] | Convertible Senior Notes [Member] |
|
|
|
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |
|
|
|
| Convertible notes carrying value |
62,398
|
61,766
|
|
| Convertible notes fair value |
61,160
|
49,873
|
|
| Fair Value Measurements Nonrecurring | Fair Value Measurements - Level 1 [Member] | 8.0% Convertible Notes [Member] |
|
|
|
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |
|
|
|
| Convertible notes carrying value |
97,385
|
97,205
|
|
| Convertible notes fair value |
$ 92,156
|
$ 92,156
|
|