Selected Quarterly Financial Data (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2012	Oct. 31, 2013	Oct. 31, 2012	Oct. 31, 2011
Quarterly Financial Information [Line Items]
Revenues	$ 1,236,773	$ 1,216,768	$ 1,173,617	$ 1,182,123	$ 1,090,001	$ 1,079,235	$ 1,057,244	$ 1,073,785	$ 4,809,281	$ 4,300,265	$ 4,246,842
Gross profit	135,202	121,002	125,404	114,244	121,585	107,607	109,328	107,365
Net income	$ 24,168	$ 16,076	$ 19,274	$ 13,382	$ 27,663	$ 12,577	$ 11,712	$ 10,630	$ 72,900	$ 62,582	$ 68,504
Net income per common share-Basic	$ 0.44	$ 0.29	$ 0.35	$ 0.25	$ 0.50	$ 0.23	$ 0.22	$ 0.20	$ 1.33	$ 1.16	$ 1.29
Net income per common share-Diluted	$ 0.43	$ 0.29	$ 0.35	$ 0.24	$ 0.50	$ 0.23	$ 0.21	$ 0.20	$ 1.30	$ 1.14	$ 1.27