Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Dec. 27, 2019	Dec. 28, 2018
Numerator:
Net income	$ 34,790	$ 26,949
Less: Undistributed earnings allocated to participating securities	857	653
Net income available to common shareholders	$ 33,933	$ 26,296
Denominator:
Weighted-average shares outstanding - Basic (in shares)	47,126	46,995
Effect of dilutive securities: Non-participating employee stock options (in shares)	873	1,288
Weighted-average shares outstanding - diluted (in shares)	47,999	48,283
Basic earnings per share (in dollars per share)	$ 0.72	$ 0.56
Diluted earnings per share (in dollars per share)	$ 0.71	$ 0.54