Fair Value Measurements - Estimated Fair Value and Carrying Value of 2019, 2020 and 2023 Notes (Detail) - USD ($) $ in Thousands	Nov. 02, 2019	Feb. 02, 2019
Convertible senior notes due 2019
Fair Value Balance Sheet Grouping Financial Statement Captions
Convertible senior notes, Fair Value		$ 334,756
Convertible senior notes, Carrying Value		344,146
Convertible senior notes due 2020
Fair Value Balance Sheet Grouping Financial Statement Captions
Convertible senior notes, Fair Value	$ 287,992	260,258
Convertible senior notes, Carrying Value	286,452	272,919
Convertible senior notes due 2023
Fair Value Balance Sheet Grouping Financial Statement Captions
Convertible senior notes, Fair Value	271,208	230,684
Convertible senior notes, Carrying Value	266,026	$ 253,689
Convertible senior notes due 2024
Fair Value Balance Sheet Grouping Financial Statement Captions
Convertible senior notes, Fair Value	263,368
Convertible senior notes, Carrying Value	$ 264,552