Restructuring Charges (Details) - USD ($)	3 Months Ended			6 Months Ended		15 Months Ended
	Jan. 31, 2016	Oct. 31, 2015	Jan. 31, 2015	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 1,000,000		$ 700,000	$ 8,500,000	$ 700,000
Restructuring reserve	0			0		$ 0
2016 Actions
Restructuring Cost and Reserve [Line Items]
Restructuring charges	400,000		0	6,200,000	0
2016 Actions | Engine Product segment
Restructuring Cost and Reserve [Line Items]
Restructuring reserve		$ 0
2015 Actions
Restructuring Cost and Reserve [Line Items]
Restructuring charges	600,000		700,000	2,300,000	700,000
2015 Actions | Engine Product segment
Restructuring Cost and Reserve [Line Items]
Expected restructuring costs			$ 5,800,000		$ 5,800,000
Restructuring charges						$ 5,800,000
One-time Termination Benefits | 2016 Actions
Restructuring Cost and Reserve [Line Items]
Expected restructuring costs		7,200,000
Restructuring charges	400,000	$ 5,800,000		6,200,000
One-time Termination Benefits | 2016 Actions | Engine Product segment
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 400,000			3,800,000
One-time Termination Benefits | 2016 Actions | Industrial Product segment
Restructuring Cost and Reserve [Line Items]
Restructuring charges				$ 2,400,000