Detail of Certain Balance Sheet Accounts (Tables)

12 Months Ended

Sep. 30, 2018

Detail Of Certain Balance Sheet Accounts [Abstract]

Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]

	Year Ended September 30,
	2018		2017
Balance at beginning of period	$	650	$	736
Additions to costs and expenses		515		294
Deductions for uncollectible receivables written off, net of recoveries		(297)		(380)
Balance at end of period	$	868	$	650

Schedule of Accounts Payable and Accrued Liabilities [Table Text Block]

	Year Ended September 30,
	2018		2017
Accounts payable, trade	$	75,293	$	63,246
Accrued compensation and benefits		34,058		33,561
Accrued insurance liabilities		6,202		6,204
Other accrued expenses		15,038		17,699
	$	130,591	$	120,710

Contracts In Progresstable [Text Block]

	Year Ended September 30,
	2018		2017
Costs incurred on contracts in progress	$	476,609	$	486,950
Estimated earnings		62,617		55,606
		539,226		542,556
Less--Billings to date		(541,606)		(559,036)
Net contracts in progress	$	(2,380)	$	(16,480)
Costs and estimated earnings in excess of billings		31,446		13,438
Less--Billings in excess of costs and estimated earnings		(33,826)		(29,918)
Net contracts in progress	$	(2,380)	$	(16,480)

Schedule of Other Assets, Noncurrent [Table Text Block]

	Year Ended September 30,
	2018		2017
Executive Savings Plan assets		747		641
Securities and equity investments		558		558
Other		4,760		2,583
Total	$	6,065	$	3,782

Schedule of Cost Method Investments [Table Text Block]

	Year Ended September 30,
	2018		2017
Carrying value	$	558	$	558
Unrealized gains		224		171
Fair value	$	782	$	729