Guarantees	3 Months Ended
Oct. 31, 2012
Guarantees [Abstract]
Guarantees	Note I – 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 October 31, 2012, AFSI had $30.2 million of outstanding debt, of which the Company guarantees half. For the three months ended October 31, 2012 and 2011, the Company recorded $0.7 million of earnings from this equity method investment. During the three months ended October 31, 2012 and 2011, the Company also recorded royalty income of $1.6 million and $1.7 million, respectively, related to AFSI. As of October 31, 2012, the Company had a contingent liability for standby letters of credit totaling $10.9 million that have been issued and are outstanding. The letters of credit guarantee payment to third parties in the event the Company is in breach of insurance contract terms as detailed in each letter of credit. At October 31, 2012, there were no amounts drawn upon these letters of credit.

Guarantees

3 Months Ended

Oct. 31, 2012

Note I – 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 October 31, 2012, AFSI had $30.2 million of outstanding debt, of which the Company guarantees half. For the three months ended October 31, 2012 and 2011, the Company recorded $0.7 million of earnings from this equity method investment. During the three months ended October 31, 2012 and 2011, the Company also recorded royalty income of $1.6 million and $1.7 million, respectively, related to AFSI.

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