Description of Business and Summary of Significant Accounting Policies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jul. 31, 2012	Jul. 31, 2011	Jul. 31, 2010
Accounting Policies [Line Items]
Investments accounted for using the equity method	$ 6.1	$ 5.4
Investments accounted for using the cost method	1.1	3.5
Advertising expense	17.0	13.7	13.6
USF charges	1.1	1.5	2.2
Percentage of consolidated revenues not exceeded by one single customer	10.00%	10.00%	10.00%
Percentage of consolidated revenues from continuing operations	8.10%	7.10%	8.40%
Percentage of gross trade accounts receivable from customers	24.30%	21.00%
Maximum [Member]
Accounting Policies [Line Items]
Amortization expense related to capitalized software	5.8	4.7	7.8
Unamortized capitalized internal use software costs	8.3	7.6
Cash and Cash Equivalents [Member]
Accounting Policies [Line Items]
Reclassified amount		9.9
Restricted Cash and Cash Equivalents [Member]
Accounting Policies [Line Items]
Reclassified amount		2.3
Other Assets [Member]
Accounting Policies [Line Items]
Reclassified amount		1.8
Income Taxes Payable [Member]
Accounting Policies [Line Items]
Reclassified amount		3.8
Customer Deposits [Member]
Accounting Policies [Line Items]
Reclassified amount		1.5
Trade Accounts Payable, Accrued Expenses, Other Current Liabilities and Other Liabilities [Member]
Accounting Policies [Line Items]
Reclassified amount		$ 0.1	$ (0.2)
Customer Lists [Member]
Accounting Policies [Line Items]
Amortization period	15
Trademarks [Member]
Accounting Policies [Line Items]
Amortization period	5
Non Compete Agreement [Member]
Accounting Policies [Line Items]
Amortization period	3
Equipment [Member]
Accounting Policies [Line Items]
Estimated useful lives of Long-Lived assets	5
Estimated useful lives of Long-Lived assets	7
Estimated useful lives of Long-Lived assets	20
Building [Member]
Accounting Policies [Line Items]
Estimated useful lives of Long-Lived assets	40
Computer Software [Member]
Accounting Policies [Line Items]
Estimated useful lives of Long-Lived assets	2
Estimated useful lives of Long-Lived assets	3
Estimated useful lives of Long-Lived assets	5
Furniture and Fixtures [Member]
Accounting Policies [Line Items]
Estimated useful lives of Long-Lived assets	5
Estimated useful lives of Long-Lived assets	7
Estimated useful lives of Long-Lived assets	10