Property, Plant and Equipment (Tables)

12 Months Ended

Sep. 30, 2022

Property, Plant and Equipment [Abstract]

Schedule of property, plant and equipment

The estimated useful lives of property, plant and equipment categories are as follows:

Category	Estimated Useful Life
Land and improvements	Land, unlimited; improvements, 15-25 years
Mineral reserves	Based on depletion
Buildings	5 - 39 years
Plants	3 - 20 years
Construction equipment	3 - 10 years
Furniture and fixtures	5 - 10 years
Leasehold improvements	The shorter of 15 years or the remaining lease term

Property, plant and equipment at September 30, 2022 and 2021 consisted of the following (in thousands):

	September 30,
	2022		2021
Construction equipment	$	402,581	$	333,966
Plants	167,625		143,172
Land and improvements	59,454		53,415
Mineral reserves	91,992		86,556
Buildings	32,566		27,163
Furniture and fixtures	7,110		6,426
Leasehold improvements	1,230		1,230
Total property, plant and equipment, gross	762,558		651,928
Accumulated depreciation, depletion and amortization	(304,935)		(250,803)
Construction in progress	23,789		3,707
Total property, plant and equipment, net	$	481,412	$	404,832