Fair value measurements (Details) - USD ($) $ in Thousands	Aug. 04, 2018	Feb. 03, 2018	Jul. 29, 2017
Level 2 \| Non-qualified deferred compensation plan
Fair value measurements
Fair value of financial liabilities	$ 20,419	$ 15,942	$ 14,303

Fair value of financial obligations, including, but not limited to, debt instruments, derivative liabilities, federal funds purchased and sold under agreements to repurchase, securities loaned or sold under agreements to repurchase, financial instruments sold not yet purchased, guarantees, line of credit, loans and notes payable, servicing liability, and trading liabilities.

No definition available.

Name:	us-gaap_FinancialLiabilitiesFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant