Consolidated Statements of Shareholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Balance at the beginning of the year at Sep. 30, 2017	$ 428,777	$ 4,440	$ 163,632	$ 261,258	$ (553)
Balance at the beginning of the year (in shares) at Sep. 30, 2017		17,760
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total comprehensive income	54,046			50,568	3,478
Exercise of stock options (in shares)		13
Exercise of stock options	630	$ 3	627
Stock-based compensation (in shares)		71
Stock-based compensation	5,366	$ 18	5,348
Issuance for employee stock purchase plan (in shares)		24
Issuance for employee stock purchase plan	1,071	$ 6	1,065
Common stock purchased and retired (in shares)		(24)
Common stock purchased and retired	(1,306)	$ (6)	(1,300)
Dividends	(16,034)			(16,034)
Balance at the end of the year (in shares) at Jun. 30, 2018		17,844
Balance at the end of the year at Jun. 30, 2018	472,550	$ 4,461	169,339	295,825	2,925
Balance at the beginning of the year at Mar. 31, 2018	472,230	$ 4,448	166,757	292,200	8,825
Balance at the beginning of the year (in shares) at Mar. 31, 2018		17,792
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total comprehensive income	3,079			8,979	(5,900)
Exercise of stock options (in shares)		9
Exercise of stock options	418	$ 2	416
Stock-based compensation (in shares)		41
Stock-based compensation	2,188	$ 11	2,177
Issuance for employee stock purchase plan (in shares)		12
Issuance for employee stock purchase plan	538	$ 3	535
Common stock purchased and retired (in shares)		(10)
Common stock purchased and retired	(549)	$ (3)	(546)
Dividends	(5,354)			(5,354)
Balance at the end of the year (in shares) at Jun. 30, 2018		17,844
Balance at the end of the year at Jun. 30, 2018	472,550	$ 4,461	169,339	295,825	2,925
Balance at the beginning of the year at Sep. 29, 2018	477,932	$ 4,464	171,407	300,585	1,476
Balance at the beginning of the year (in shares) at Sep. 29, 2018		17,856
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total comprehensive income	31,361			38,246	(6,885)
Conversion of tangible equity units (in shares)		781
Conversion of tangible equity units		$ 195	(195)
Exercise of stock options (in shares)		23
Exercise of stock options	1,140	$ 6	1,134
Stock-based compensation (in shares)		88
Stock-based compensation	7,515	$ 22	7,493
Issuance for employee stock purchase plan (in shares)		16
Issuance for employee stock purchase plan	557	$ 4	553
Common stock purchased and retired (in shares)		(28)
Common stock purchased and retired	(1,384)	$ (7)	(1,377)
Dividends	(16,355)			(16,355)
Balance at the end of the year (in shares) at Jun. 29, 2019		18,736
Balance at the end of the year at Jun. 29, 2019	494,539	$ 4,684	179,015	316,249	(5,409)
Balance at the beginning of the year at Mar. 30, 2019	485,054	$ 4,475	176,918	308,279	(4,618)
Balance at the beginning of the year (in shares) at Mar. 30, 2019		17,900
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total comprehensive income	12,794			13,585	(791)
Conversion of tangible equity units (in shares)		781
Conversion of tangible equity units		$ 195	(195)
Exercise of stock options (in shares)		20
Exercise of stock options	996	$ 5	991
Stock-based compensation (in shares)		55
Stock-based compensation	2,296	$ 14	2,282
Common stock purchased and retired (in shares)		(20)
Common stock purchased and retired	(986)	$ (5)	(981)
Dividends	(5,615)			(5,615)
Balance at the end of the year (in shares) at Jun. 29, 2019		18,736
Balance at the end of the year at Jun. 29, 2019	$ 494,539	$ 4,684	$ 179,015	$ 316,249	$ (5,409)