Contracts-in-Process and Long-Term Receivables (Narrative) (Detail) (USD $)	Sep. 30, 2012	Dec. 31, 2011
Allowance for doubtful accounts receivable	$ 200,000	$ 200,000
Notes receivable	23,953,000
Billed receivables excluding billed orbital receivables	97,600,000	104,500,000
Billed orbital receivables	3,200,000	3,500,000
Orbital receivables for satellites under construction	99,900,000	141,500,000
Unbilled receivables other than orbital receivables	77,100,000	40,000,000
Financing receivables as reported	$ 23,953,000