Guarantees	12 Months Ended
Jul. 31, 2013
Guarantees [Abstract]
Guarantees	NOTE M Guarantees The Company and Caterpillar Inc. equally own the shares of Advanced Filtration Systems Inc. (AFSI), an unconsolidated joint venture, and guarantee certain debt of the joint venture. As of July 31, 2013, the joint venture had $29.1 million of outstanding debt, of which the Company guarantees half. In addition, during Fiscal 2013, 2012, and 2011, the Company recorded its equity in earnings of this equity method investment of $2.3 million, $2.0 million, and $1.6 million and royalty income of $6.0 million, $6.2 million, and $6.2 million, respectively, related to AFSI. At July 31, 2013 and 2012, the Company had a contingent liability for standby letters of credit totaling $12.2 million and $10.9 million, respectively, which have been issued and are outstanding. The letters of credit guarantee payment to third parties in the event the Company is in breach of a specified bond financing agreement and insurance contract terms as detailed in each letter of credit. At July 31, 2013 and 2012, there were no amounts drawn upon these letters of credit.

Guarantees

12 Months Ended

Jul. 31, 2013

NOTE M Guarantees

The Company and Caterpillar Inc. equally own the shares of Advanced Filtration Systems Inc. (AFSI), an unconsolidated joint venture, and guarantee certain debt of the joint venture. As of July 31, 2013, the joint venture had $29.1 million of outstanding debt, of which the Company guarantees half. In addition, during Fiscal 2013, 2012, and 2011, the Company recorded its equity in earnings of this equity method investment of $2.3 million, $2.0 million, and $1.6 million and royalty income of $6.0 million, $6.2 million, and $6.2 million, respectively, related to AFSI.

At July 31, 2013 and 2012, the Company had a contingent liability for standby letters of credit totaling $12.2 million and $10.9 million, respectively, which have been issued and are outstanding. The letters of credit guarantee payment to third parties in the event the Company is in breach of a specified bond financing agreement and insurance contract terms as detailed in each letter of credit. At July 31, 2013 and 2012, there were no amounts drawn upon these letters of credit.