Balance Sheet Details (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Jun. 30, 2012 Y	Sep. 30, 2011
Accounts receivable:
Trade and other receivables	$ 16,581	$ 20,259
Long-term contracts:
Billed	99,252	89,056
Unbilled	230,806	142,070
Allowance for doubtful accounts	(671)	(395)
Total accounts receivable	345,968	250,990
Less estimated amounts not currently due	(22,850)	(23,700)
Current accounts receivable	323,118	227,290
Period that receivables will not be collected within to be classified as not currently due (in years)	1
Inventories:
Work in process and inventoried costs under long-term contracts	73,096	71,855
Customer advances	(24,211)	(34,582)
Raw material and purchased parts	737	1,086
Net inventories	$ 49,622	$ 38,359