Condensed Consolidated Statements of Income and Comprehensive Income (Unaudited) (USD $) In Thousands, except Per Share data	3 Months Ended		6 Months Ended
	Jul. 31, 2011	Aug. 01, 2010	Jul. 31, 2011	Aug. 01, 2010
Condensed Consolidated Statements of Income and Comprehensive Income [Abstract]
Merchandise sales	$ 1,300,473	$ 1,216,682	$ 2,614,822	$ 2,450,277
Services sales	177,945	165,305	345,041	318,592
Other revenue	9,135	8,553	18,056	16,824
Net sales	1,487,553	1,390,540	2,977,919	2,785,693
Cost of merchandise sales	916,736	869,226	1,836,212	1,739,068
Cost of services sales	124,698	116,466	245,252	229,214
Cost of other revenue	9,135	8,553	18,056	16,824
Total cost of sales	1,050,569	994,245	2,099,520	1,985,106
Gross profit	436,984	396,295	878,399	800,587
Operating, general and administrative expenses	326,708	304,288	646,440	605,319
Operating income	110,276	92,007	231,959	195,268
Interest expense, net	(14,255)	(14,590)	(28,702)	(29,933)
Income before income tax expense and equity in income from Banfield	96,021	77,417	203,257	165,335
Income tax expense	(37,624)	(31,150)	(76,530)	(64,914)
Equity in income from Banfield	2,783	2,119	5,358	3,557
Net income	61,180	48,386	132,085	103,978
Other comprehensive (loss) income, net of income tax:
Foreign currency translation adjustments	(194)	(695)	2,572	1,722
Other	5	0	13	0
Comprehensive income	$ 60,991	$ 47,691	$ 134,670	$ 105,700
Earnings per common share:
Basic	$ 0.54	$ 0.41	$ 1.17	$ 0.88
Diluted	$ 0.54	$ 0.41	$ 1.15	$ 0.87
Weighted average shares outstanding:
Basic	112,396	117,079	112,972	117,528
Diluted	114,341	119,423	115,039	119,917