Cash, Cash Equivalents and Marketable Securities - Summary of Estimated Fair Value of Cash, Cash Equivalents and Marketable Securities (Detail) - USD ($) $ in Thousands	May 05, 2018	Feb. 03, 2018	Apr. 29, 2017	Jan. 28, 2017
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost, Cash and cash equivalents	$ 29,063	$ 24,041	$ 22,320	$ 20,247
Estimated Fair Value, Cash and cash equivalents	29,063	24,041
Amortized Cost, Marketable securities	89,107	97,985
Gross Unrealized Holding Gains, Marketable securities		9
Gross Unrealized Holding Losses, Marketable securities	(189)	(130)
Estimated Fair Value, Marketable securities	88,918	97,864
Cash [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost, Cash and cash equivalents	28,093	21,911
Estimated Fair Value, Cash and cash equivalents	28,093	21,911
Money Market Funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost, Cash and cash equivalents	168	2,130
Estimated Fair Value, Cash and cash equivalents	168	2,130
State and Local Government Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost, Cash and cash equivalents	802
Estimated Fair Value, Cash and cash equivalents	802
Amortized Cost, Marketable securities	67,852	68,620
Gross Unrealized Holding Gains, Marketable securities		9
Gross Unrealized Holding Losses, Marketable securities	(189)	(130)
Estimated Fair Value, Marketable securities	67,663	68,499
Variable-rate Demand Notes [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost, Marketable securities	21,255	29,365
Estimated Fair Value, Marketable securities	$ 21,255	$ 29,365