Condensed Consolidated Statements of Income and Comprehensive Income (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jul. 29, 2012	Jul. 31, 2011	Jul. 29, 2012	Jul. 31, 2011
Condensed Consolidated Statements of Income and Comprehensive Income [Abstract]
Merchandise sales	$ 1,419,383	$ 1,300,473	$ 2,858,942	$ 2,614,822
Services sales	190,867	177,945	371,881	345,041
Other revenue	9,417	9,135	18,737	18,056
Net sales	1,619,667	1,487,553	3,249,560	2,977,919
Cost of merchandise sales	986,885	916,736	1,981,393	1,836,212
Cost of services sales	134,550	124,698	263,241	245,252
Cost of other revenue	9,417	9,135	18,737	18,056
Total cost of sales	1,130,852	1,050,569	2,263,371	2,099,520
Gross profit	488,815	436,984	986,189	878,399
Operating, general and administrative expenses	352,755	326,708	695,778	646,440
Operating income	136,060	110,276	290,411	231,959
Interest expense, net	(13,550)	(14,255)	(27,679)	(28,702)
Income before income tax expense and equity in income from Banfield	122,510	96,021	262,732	203,257
Income tax expense	(48,333)	(37,624)	(96,505)	(76,530)
Equity in income from Banfield	4,343	2,783	6,976	5,358
Net income	78,520	61,180	173,203	132,085
Other comprehensive income, net of income tax:
Foreign currency translation adjustments	(1,384)	(194)	(165)	2,572
Other	0	5	(3)	13
Comprehensive income	$ 77,136	$ 60,991	$ 173,035	$ 134,670
Earnings per common share:
Basic	$ 0.73	$ 0.54	$ 1.59	$ 1.17
Diluted	$ 0.71	$ 0.54	$ 1.57	$ 1.15
Weighted average shares outstanding:
Basic	108,260	112,396	108,595	112,972
Diluted	109,934	114,341	110,507	115,039