Quarterly financial data (unaudited) (Detail) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Feb. 02, 2018 USD ($) item $ / shares	Nov. 03, 2017 USD ($) item $ / shares	Aug. 04, 2017 USD ($) item $ / shares	May 05, 2017 USD ($) item $ / shares	Feb. 03, 2017 USD ($) item $ / shares	Oct. 28, 2016 USD ($) item $ / shares	Jul. 29, 2016 USD ($) item $ / shares	Apr. 29, 2016 USD ($) item $ / shares	Feb. 02, 2018 USD ($) item $ / shares	Feb. 03, 2017 USD ($) item $ / shares	Jan. 29, 2016 USD ($) $ / shares
Selected unaudited quarterly financial data
Number of weeks in a quarter | item	13	13	13	13	14	13	13	13
Net sales	$ 6,129,431	$ 5,903,606	$ 5,828,305	$ 5,609,625	$ 6,009,246	$ 5,320,029	$ 5,391,891	$ 5,265,432	$ 23,470,967	$ 21,986,598	$ 20,368,562
Gross profit	1,965,398	1,766,456	1,790,522	1,698,983	1,900,747	1,587,510	1,681,767	1,612,614	7,221,359	6,782,638	6,306,091
Operating profit	623,446	417,431	493,146	473,795	680,618	392,991	509,097	480,743	2,007,818	2,063,449	1,940,294
Net income	$ 712,155	$ 252,533	$ 294,783	$ 279,489	$ 414,176	$ 235,315	$ 306,518	$ 295,124	$ 1,538,960	$ 1,251,133	$ 1,165,080
Basic earnings per share (in dollars per share) | $ / shares	$ 2.63	$ 0.93	$ 1.08	$ 1.02	$ 1.50	$ 0.84	$ 1.08	$ 1.03	$ 5.64	$ 4.45	$ 3.96
Diluted earnings per share (in dollars per share) | $ / shares	$ 2.63	$ 0.93	$ 1.08	$ 1.02	$ 1.49	$ 0.84	$ 1.08	$ 1.03	$ 5.63	$ 4.43	$ 3.95
Number of stores acquired | item			15			42
Number of stores under assumed lease obligations | item			300
Number of stores closing | item	35					40			35
Number of locations | item					12					12
Selling, general and administrative expenses	$ 28,300		$ 7,300		$ (4,500)	$ 11,000
Selling, general and administrative expenses, net of tax	$ 17,600		$ 4,400		$ (2,800)	$ 6,700
Effect of pre-tax asset purchase on earnings per diluted share (in dollars per share) | $ / shares	$ (0.07)		$ (0.02)		$ 0.01	$ (0.02)