Basis of presentation and accounting policies - Impairment, Goodwill, Balance sheet detail (Detail) - USD ($)	12 Months Ended
	Feb. 02, 2018	Feb. 03, 2017	Jan. 29, 2016
Impairment of long-lived assets
Minimum period for which stores are open to be reviewed for impairment	3 years
Impairment charges included in SG&A expense	$ 7,800,000	$ 6,300,000	$ 5,900,000
Goodwill and other intangible assets
Impairment of intangible assets	0	0	$ 0
Accrued expenses and other liabilities
Compensation and benefits	118,755,000	91,243,000
Insurance	95,411,000	85,240,000
Taxes (other than taxes on income)	164,451,000	175,099,000
Other	171,041,000	149,284,000
Accrued expenses and other	549,658,000	500,866,000
Operating leases and related liabilities
Deferred rent liability	65,900,000	61,100,000
Contingent rent liability	2,700,000	3,500,000
Noncurrent Other liabilities
Insurance	134,256,000	137,743,000
Deferred rent	65,856,000	61,082,000
Deferred gain on sale leaseback	44,781,000	49,259,000
Lease liabilities for closed stores	24,174,000	3,483,000
Other	36,877,000	28,215,000
Noncurrent other liabilities	$ 305,944,000	$ 279,782,000