Financing Arrangements Financing Balances at Period End (Details) - USD ($) $ in Thousands	Oct. 31, 2018	Jul. 31, 2018	Oct. 31, 2017
Debt Instrument [Line Items]
Long-term Debt	$ 244,038
Total debt	246,678	$ 246,678	$ 183,092
Less: Current debt	1,327	1,327	2,027
Total long-term debt	245,351	245,351	181,065
Insurance Financing Agreement [Member]
Debt Instrument [Line Items]
Short-term Debt	$ 738	738	$ 650
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Interest Rate at Period End	4.59%		3.88%
Long-term Debt	$ 243,300	243,300	$ 178,200
Equipment Security Note [Member]
Debt Instrument [Line Items]
Long-term Debt		0	482
Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 2,640	$ 2,640	$ 3,760