Balance Sheet Details (Details) (USD $)	6 Months Ended
	Mar. 31, 2013	Sep. 30, 2012
Accounts receivable:
Trade and other receivables	$ 21,060,000	$ 17,543,000
Long-term contracts:
Billed	108,774,000	91,132,000
Unbilled	305,713,000	264,555,000
Allowance for doubtful accounts	(651,000)	(463,000)
Total accounts receivable	434,896,000	372,767,000
Less estimated amounts not currently due	(20,830,000)	(22,070,000)
Current accounts receivable	414,066,000	350,697,000
Period that receivables will not be collected within to be classified as not currently due	1 year
Inventories
Work in process and inventoried costs under long-term contracts	71,885,000	78,796,000
Customer advances	(21,601,000)	(27,288,000)
Raw materials and purchased parts	708,000	858,000
Net inventories	50,992,000	52,366,000
Costs incurred outside the scope of work or in advance of a contract award	$ 1,600,000	$ 1,900,000