Borrowings and Credit Arrangements - Interest Expense under Convertible Notes (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 29, 2014	Mar. 30, 2013	Mar. 29, 2014	Mar. 30, 2013
Debt Conversion [Line Items]
Non-cash interest expense			$ 35,820	$ 41,387
Convertible Notes Payable [Member]
Debt Conversion [Line Items]
Amortization of debt discount	8,341	13,621	19,887	29,265
Amortization of deferred financing costs	413	790	1,063	1,698
Principal accretion	7,584	1,789	7,584	1,789
Non-cash interest expense	12,564	16,200	28,534	32,752
2.00% accrued interest	4,751	8,616	12,870	17,226
Interest expense, net	$ 17,315	$ 24,816	$ 41,404	$ 49,978