Financing Receivables and Allowance for Credit Losses (Detail) (USD $)	Jun. 29, 2012		Sep. 30, 2011
Financing Receivables [Line Items]
Accounts receivable with contractual maturities of more than one year, Gross amount	$ 26,800,000		$ 16,200,000
Accounts receivable with contractual maturities of more than one year, Allowance for doubtful accounts	0		0
Accounts receivable with contractual maturities of more than one year, Net amount	26,800,000		16,200,000
Accounts receivable with contractual maturities of more than one year, Amount past due	900,000		1,200,000
Note receivable from related party	5,400,000		8,800,000
Note receivable, Amount past due	0		0
Total short-term investment	47,155,000	[1]	19,205,000	[1],[2]
Short-term investment, Amount past due	$ 0		$ 0

[1] Represents a loan to CPTC. See Note 15, "Variable Interest Entity."

[2] The condensed consolidated balance sheet as of September 30, 2011 was derived from audited financial statements as of that date, but does not include all disclosures required by accounting principles generally accepted in the United States of America.