Fair Value - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Sep. 19, 2019
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Land and Development impairments			$ 13.0
Maximum eligible receivables that may be sold				$ 650.0
Minimum [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Estimated loss on sale of accounts receivable by quarter		$ 2.0
Maximum [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Estimated loss on sale of accounts receivable by quarter		$ 4.0
Mineral Rights [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Land and Development impairments	$ 13.0