RESTATEMENT OF CONSOLIDATED FINANCIAL STATEMENTS (Statement of shareholders' equity) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Apr. 02, 2016	Jan. 02, 2016	Sep. 30, 2017	Oct. 01, 2016	Oct. 03, 2015
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Beginning Balance				$ 799,524				$ 760,912	$ 799,524	$ 760,912	$ 776,990
Issuance of stock for services rendered									750	551	1,049
Repurchase of common stock									$ (18,197)	(14,551)	(77,872)
Treasury Stock, Shares, Acquired									(944,840.00)
Exercise of stock options									$ 509	410	694
Issuance of shares for market-based restricted stock and time-based restricted stock									0	0	0
Excess tax benefits from stock based compensation									(4,392)	197	540
Equity-based compensation expense									10,972	5,179	10,940
Net income	$ 41,225	$ 34,808	$ 32,670	17,396	$ 10,761	$ 32,925	$ 5,109	(340)	126,099	48,455	51,912
Foreign currency translation adjustment									1,960	624	(3,360)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax									1,815	(462)	0
Unamortized pension costs									990	(1,791)	19
Comprehensive income									130,864	46,826	48,571
Ending Balance	920,030				799,524				920,030	799,524	760,912
As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Beginning Balance				806,518				769,249	806,518	769,249	786,600
Issuance of stock for services rendered									750	551	1,049
Repurchase of common stock									(18,197)	(14,551)	(77,872)
Exercise of stock options									509	410	694
Issuance of shares for market-based restricted stock and time-based restricted stock									0	0	0
Excess tax benefits from stock based compensation									(4,392)	197	540
Equity-based compensation expense									10,972	5,179	10,940
Net income	36,576	30,811	29,041	15,583	10,329	31,785	5,089	(91)	112,011	47,112	50,639
Foreign currency translation adjustment									1,960	624	(3,360)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax									1,815	(462)
Unamortized pension costs									990	(1,791)	19
Comprehensive income									116,776	45,483	47,298
Ending Balance	912,936				806,518				912,936	806,518	769,249
Effect of Restatement
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Beginning Balance				(6,994)				(8,337)	(6,994)	(8,337)	(9,610)
Net income	4,649	$ 3,997	$ 3,629	1,813	432	$ 1,140	$ 20	(249)	14,088	1,343	1,273
Comprehensive income									14,088	1,343	1,273
Ending Balance	7,094				(6,994)				7,094	(6,994)	(8,337)
Common Stock
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Beginning Balance				$ 498,676				$ 492,339	$ 498,676	$ 492,339	$ 479,116
Beginning Balance, shares				70,420,000				71,240,000	70,420,000	71,240,000	76,626,000
Issuance of stock for services rendered									$ 750	$ 551	$ 1,049
Issuance of stock for services rendered, shares									45,000	50,000	83,000
Repurchase of common stock									$ 0		$ 0
Treasury Stock, Shares, Acquired									(945,000)	(1,408,000)	(6,405,000)
Exercise of stock options									$ 509	$ 410	$ 694
Exercise of stock options, shares									61,000	53,000	75,000
Issuance of shares for market-based restricted stock and time-based restricted stock									$ 0	$ 0	$ 0
Issuance of shares for market-based restricted stock and time-based restricted stock, shares									616,000	485,000	861,000
Excess tax benefits from stock based compensation									$ (4,392)	$ 197	$ 540
Equity-based compensation expense									10,972	5,179	10,940
Ending Balance	$ 506,515				$ 498,676				$ 506,515	$ 498,676	$ 492,339
Ending Balance, shares	70,197,000				70,420,000				70,197,000	70,420,000	71,240,000
Common Stock | As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Beginning Balance				$ 498,676				$ 492,339	$ 498,676	$ 492,339	$ 479,116
Beginning Balance, shares				70,420,000				71,240,000	70,420,000	71,240,000	76,626,000
Issuance of stock for services rendered									$ 750	$ 551	$ 1,049
Issuance of stock for services rendered, shares									45,000	50,000	83,000
Repurchase of common stock											$ 0
Treasury Stock, Shares, Acquired									(945,000)	(1,408,000)	(6,405,000)
Exercise of stock options									$ 509	$ 410	$ 694
Exercise of stock options, shares									61,000	53,000	75,000
Issuance of shares for market-based restricted stock and time-based restricted stock											$ 0
Issuance of shares for market-based restricted stock and time-based restricted stock, shares									616,000	485,000	861,000
Excess tax benefits from stock based compensation									$ (4,392)	$ 197	$ 540
Equity-based compensation expense									10,972	5,179	10,940
Ending Balance	$ 506,515				$ 498,676				$ 506,515	$ 498,676	$ 492,339
Ending Balance, shares	70,197,000				70,420,000				70,197,000	70,420,000	71,240,000
Treasury Stock
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Beginning Balance				$ (139,407)				$ (124,856)	$ (139,407)	$ (124,856)	$ (46,984)
Issuance of stock for services rendered									0		0
Repurchase of common stock									$ (18,197)	$ (14,551)	$ (77,872)
Treasury Stock, Shares, Acquired									(945,000)	(1,408,000)	(6,405,000)
Ending Balance	$ (157,604)				$ (139,407)				$ (157,604)	$ (139,407)	$ (124,856)
Treasury Stock | As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Beginning Balance				(139,407)				(124,856)	(139,407)	(124,856)	(46,984)
Issuance of stock for services rendered											0
Repurchase of common stock									(18,197)	(14,551)	(77,872)
Ending Balance	(157,604)				(139,407)				(157,604)	(139,407)	(124,856)
Retained earnings
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Beginning Balance				442,981				394,526	442,981	394,526	342,614
Net income									126,099	48,455	51,912
Foreign currency translation adjustment											0
Unamortized pension costs											0
Comprehensive income									126,099	48,455	51,912
Ending Balance	569,080				442,981				569,080	442,981	394,526
Retained earnings | As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Beginning Balance				449,975				402,863	449,975	402,863	352,224
Net income									112,011	47,112	50,639
Foreign currency translation adjustment									0	0
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax									0	0
Unamortized pension costs									0	0
Comprehensive income									112,011	47,112	50,639
Ending Balance	561,986				449,975				561,986	449,975	402,863
Retained earnings | Effect of Restatement
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Beginning Balance				(6,994)				(8,337)	(6,994)	(8,337)	(9,610)
Net income									14,088	1,343	1,273
Comprehensive income									14,088	1,343	1,273
Ending Balance	7,094				(6,994)				7,094	(6,994)	(8,337)
Accumulated Other Comprehensive Income
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Beginning Balance				(2,726)				(1,097)	(2,726)	(1,097)	2,244
Net income										0	0
Foreign currency translation adjustment									1,960	624	(3,360)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax									1,815	(462)
Unamortized pension costs									990	(1,791)	19
Comprehensive income									4,765	(1,629)	(3,341)
Ending Balance	2,039				(2,726)				2,039	(2,726)	(1,097)
Accumulated Other Comprehensive Income | As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Beginning Balance				$ (2,726)				$ (1,097)	(2,726)	(1,097)	2,244
Net income											0
Foreign currency translation adjustment									1,960	624	(3,360)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax									1,815	(462)
Unamortized pension costs									990	(1,791)	19
Comprehensive income									4,765	(1,629)	(3,341)
Ending Balance	$ 2,039				$ (2,726)				$ 2,039	$ (2,726)	$ (1,097)