Compensation Plans (Tables)

6 Months Ended

Mar. 30, 2013

Compensation Plans

Schedule of assumptions used in estimating the grant-date fair value of employee stock options and similar instruments

	Twenty-six weeks ended
	March 30, 2013			March 24, 2012
Average expected life	6 years			6 years
Average volatility	81		%	67		%
Dividend yield	—			—
Risk-free interest rate	1.02		%	1.39		%
Weighted average fair value	$	31.02		$	32.93

Schedule of assumptions used in estimating the grant-date fair value of employees' purchase rights under Employee Stock Purchase Plan

	Twenty-six weeks ended
	March 30, 2013			March 24, 2012
Average expected life	6 months			6 months
Average volatility	114		%	53		%
Dividend yield	—			—
Risk-free interest rate	0.14		%	0.03		%
Weighted average fair value	$	10.82		$	13.98