Guarantees	6 Months Ended
Jan. 31, 2016
Guarantees [Abstract]
Guarantees	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 January 31, 2016, AFSI had $20.3 million of outstanding debt, of which the Company guarantees half. The Company recorded a $0.1 million loss and $0.6 million of earnings from this equity method investment during the three months ended January 31, 2016 and 2015, respectively. The Company recorded a $1.2 million loss and $1.5 million of earnings from this equity method investment during the six months ended January 31, 2016 and 2015, respectively. During the three months ended January 31, 2016 and 2015, the Company recorded royalty income of $0.8 million and $1.5 million, respectively, related to AFSI. During the six months ended January 31, 2016 and 2015, the Company recorded royalty income of $2.6 million and $3.1 million, respectively, related to AFSI. As of January 31, 2016, the Company had a contingent liability for standby letters of credit totaling $7.8 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 January 31, 2016, there were no amounts drawn upon these letters of credit.

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 January 31, 2016, AFSI had $20.3 million of outstanding debt, of which the Company guarantees half. The Company recorded a $0.1 million loss and $0.6 million of earnings from this equity method investment during the three months ended January 31, 2016 and 2015, respectively. The Company recorded a $1.2 million loss and $1.5 million of earnings from this equity method investment during the six months ended January 31, 2016 and 2015, respectively. During the three months ended January 31, 2016 and 2015, the Company recorded royalty income of $0.8 million and $1.5 million, respectively, related to AFSI. During the six months ended January 31, 2016 and 2015, the Company recorded royalty income of $2.6 million and $3.1 million, respectively, related to AFSI.

As of January 31, 2016, the Company had a contingent liability for standby letters of credit totaling $7.8 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 January 31, 2016, there were no amounts drawn upon these letters of credit.