Stockholders' Equity (Details) (USD $)	0 Months Ended					3 Months Ended								12 Months Ended			0 Months Ended
	Aug. 07, 2013	Feb. 07, 2013	Aug. 06, 2012	Feb. 07, 2012	Dec. 15, 2011	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	Dec. 05, 2012 Subsequent Event [Member]
Class of Stock [Line Items]
Share repurchase program, maximum amount authorized					$ 150,000,000												$ 300,000,000
Number of shares purchased						960,000	0	0	460,000	0	321,000	0	663,000	1,420,728	984,027
Cost of common stock repurchased						123,000,000			44,400,000		25,000,000		46,100,000	167,334,000	71,150,000
Share repurchase program, remaining authorized amount														61,500,000
Average purchase price per share (usd per share)						$ 128.06			$ 96.34		$ 77.89		$ 69.60
Dividends on common stock	1,500,000	1,400,000	1,400,000	1,400,000										2,918,000	2,857,000	2,816,000
Cash dividend, per share (usd per share)	$ 0.03	$ 0.03	$ 0.03	$ 0.03										$ 0.03
Date of record	Jul. 24, 2013	Jan. 25, 2013	Jul. 24, 2012	Jan. 25, 2012
Common stock purchase right versus preferred share purchase right														0.5
Percentage of acquisition of beneficial ownership														20.00%
Purchase price of the Right, subject to adjustment (usd per right)														$ 450
Percentage of assets or earning power sold														50.00%
Board of Directors may redeem the rights at, price per right						$ 0.01								$ 0.01