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Additions made to capitalized computer software costs during the period.

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Amount of gain (loss) on sale or disposal of property, plant and equipment assets, including oil and gas property and timber property.

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Property, Plant and Equipment (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended			60 Months Ended
	Jun. 30, 2019	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2019	Oct. 01, 2018
PROPERTY, PLANT AND EQUIPMENT
Accumulated depreciation and amortization		$ (160,271)	$ (144,782)		$ (160,271)
Property, plant and equipment - net		144,969	117,546		144,969	$ 117,546
Proceeds from sale of property	$ 44,900	44,891
Gain on sale of real estate	$ 32,500	32,510		$ (405)
Development expense		50,132	52,398	52,652
Depreciation of plant and equipment and amortization of leasehold improvements		22,600	19,500	17,800
Land and land improvements
PROPERTY, PLANT AND EQUIPMENT
Property, plant and equipment, Gross		7,348	13,132		7,348
Buildings and improvements
PROPERTY, PLANT AND EQUIPMENT
Property, plant and equipment, Gross		$ 48,191	57,959		$ 48,191
Buildings and improvements \| Minimum
PROPERTY, PLANT AND EQUIPMENT
Estimated life (years)		15 years
Buildings and improvements \| Maximum
PROPERTY, PLANT AND EQUIPMENT
Estimated life (years)		39 years
Two Buildings on Existing Campus
PROPERTY, PLANT AND EQUIPMENT
Lease term		5 years			5 years
Machinery and other equipment
PROPERTY, PLANT AND EQUIPMENT
Property, plant and equipment, Gross		$ 107,297	81,727		$ 107,297
Machinery and other equipment \| Minimum
PROPERTY, PLANT AND EQUIPMENT
Estimated life (years)		5 years
Machinery and other equipment \| Maximum
PROPERTY, PLANT AND EQUIPMENT
Estimated life (years)		10 years
Software
PROPERTY, PLANT AND EQUIPMENT
Property, plant and equipment, Gross		$ 108,526	84,631		108,526
Costs related to the purchase and development of software		3,100	22,500	40,600	138,900
Addition to capitalized software expenses		1,600	7,500	16,700
Development expense		$ 1,500	15,000	$ 23,900
Software \| Minimum
PROPERTY, PLANT AND EQUIPMENT
Estimated life (years)		3 years
Software \| Maximum
PROPERTY, PLANT AND EQUIPMENT
Estimated life (years)		7 years
Leasehold improvements
PROPERTY, PLANT AND EQUIPMENT
Property, plant and equipment, Gross		$ 17,064	11,991		17,064
Construction and internal-use software development in progress
PROPERTY, PLANT AND EQUIPMENT
Property, plant and equipment, Gross		$ 16,814	$ 12,888		$ 16,814