Net Income per Common Share - Reconciliation of Numerator and Denominator of Basic and Diluted Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended																12 Months Ended
	Jul. 31, 2013		Apr. 30, 2013		Jan. 31, 2013		Oct. 31, 2012		Jul. 31, 2012		Apr. 30, 2012		Jan. 31, 2012		Oct. 31, 2011		Jul. 31, 2013		Jul. 31, 2012		Jul. 31, 2011
Earnings Per Share [Line Items]
Income (Loss) from Continuing Operations Attributable to Parent																	$ (140,816)		$ 102,471		$ 105,957
Payments of Ordinary Dividends, Common Stock																	39,243		38,899		38,064
Denominator for basic net income per share for both Class A and Class B																	51,330		52,453		52,639
Plus: Effect of dilutive stock options																	0		368		494
Denominator for diluted net income per share for both Class A and Class B																	51,330		52,821		53,133
Class A nonvoting common stock [Member]
Earnings Per Share [Line Items]
Income (Loss) from Continuing Operations Attributable to Parent																	(141,054)		102,242		105,734
Income (Loss) from Continuing Operations, Per Basic Share	$ (3.41)	[1]	$ 0.41	[1]	$ (0.22)	[1]	$ 0.50	[1]	$ 0.40		$ 0.52		$ 0.50		$ 0.53		$ (2.75)	[1]	$ 1.95		$ 2.01
Income (Loss) from Continuing Operations, Per Diluted Share	$ (3.41)	[1]	$ 0.41	[1]	$ (0.22)	[1]	$ 0.50	[1]	$ 0.40	[1]	$ 0.51	[1]	$ 0.50	[1]	$ 0.52	[1]	$ (2.75)	[1]	$ 1.94	[1]	$ 1.99
Income (Loss) from Discontinued Operations, Net of Tax, Per Basic Share																	$ (0.27)		$ (2.30)		$ 0.05
Income (Loss) from Discontinued Operations, Net of Tax, Per Diluted Share																	$ (0.27)		$ (2.29)		$ 0.05
Earnings Per Share, Basic																	$ (3.02)		$ (0.35)		$ 2.06
Earnings Per Share, Diluted																	$ (3.02)		$ (0.35)		$ 2.04
Class B voting common stock [Member]
Earnings Per Share [Line Items]
Income (Loss) from Continuing Operations Attributable to Parent																	(141,856)		101,419		104,908
Income (Loss) from Continuing Operations, Per Basic Share																	$ (2.76)		$ 1.93		$ 1.99
Income (Loss) from Continuing Operations, Per Diluted Share																	$ (2.76)		$ 1.92		$ 1.97
Income (Loss) from Discontinued Operations, Net of Tax, Per Basic Share																	$ (0.27)		$ (2.29)		$ 0.05
Income (Loss) from Discontinued Operations, Net of Tax, Per Diluted Share																	$ (0.27)		$ (2.28)		$ 0.05
Earnings Per Share, Basic																	$ (3.03)		$ (0.36)		$ 2.04
Earnings Per Share, Diluted																	$ (3.03)		$ (0.36)		$ 2.03
Restricted Stock [Member]
Earnings Per Share [Line Items]
Payments of Ordinary Dividends, Common Stock																	(238)		(229)		(223)
Preferential Dividends on Class A Nonvoting Common Stock [Member]
Earnings Per Share [Line Items]
Payments of Ordinary Dividends, Common Stock																	797		818		820
Preferential Dividends on Dilutive Shares [Member]
Earnings Per Share [Line Items]
Payments of Ordinary Dividends, Common Stock																	$ (5)		$ (5)		$ (6)

[1] The sum of the quarters does not equal the year-to-date total for fiscal 2013 and fiscal 2012 due to the quarterly changes inweighted-average shares outstanding.