Deferred Revenue And Financing Receivables (Details) (USD $)	3 Months Ended		12 Months Ended
	Dec. 31, 2011 months	Jan. 01, 2011	Sep. 30, 2011
Maximum payment terms on software purchases for credit-worthy customers (in months)	24
Amounts due from customers for contracts with extended payment terms	$ 75,600,000		$ 72,300,000
Reserve for credit losses	0		0
Uncollectible financing receivables written off	0		0
Sale of finance receivable	6,300,000	0
Accounts Receivable [Member]
Current receivables from contracts	61,000,000		55,200,000
Other Assets [Member]
Billed but uncollected maintenance receivable	84,400,000		93,000,000
Long-term receivables from contracts	$ 14,600,000		$ 17,100,000