Segment Information Geographic Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jul. 31, 2021	Apr. 30, 2021	Jan. 31, 2021	Oct. 31, 2020	Jul. 31, 2020	Apr. 30, 2020	Jan. 31, 2020	Oct. 31, 2019	Jul. 31, 2021	Jul. 31, 2020	Jul. 31, 2019
Segment Reporting Information [Line Items]
Revenues	$ 204,202	$ 889,078	$ 684,644	$ 131,786	$ 77,209	$ 694,087	$ 924,638	$ 267,770	$ 1,909,710	$ 1,963,704	$ 2,271,575
Property, Plant and Equipment, Net	2,067,876				2,192,679				2,067,876	2,192,679
Canadian [Member]
Segment Reporting Information [Line Items]
Revenues										223,300	308,100
Property, Plant and Equipment, Net	288,400				291,700				288,400	291,700
Geographic Distribution, Foreign [Member]
Segment Reporting Information [Line Items]
Revenues									192,440	307,743	406,513
Property, Plant and Equipment, Net	421,779				432,987				421,779	432,987
Geographic Distribution, Domestic [Member]
Segment Reporting Information [Line Items]
Revenues									1,717,270	1,655,961	$ 1,865,062
Property, Plant and Equipment, Net	$ 1,646,097				$ 1,759,692				$ 1,646,097	$ 1,759,692