Accumulated Other Comprehensive Loss (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jul. 01, 2012	Jul. 03, 2011	Jul. 01, 2012	Jul. 03, 2011	Apr. 03, 2011
Summary of accumulated other comprehensive loss
Beginning, balance	$ (80,256)		$ (80,820)	$ (63,433)	$ (63,063)
Pre-tax Activity	934	616	1,864	1,228
Tax Effect	(367)	(242)	(733)	(484)
Ending, balance	(79,689)	(62,689)	(79,689)	(62,689)	(63,063)
Net pension activity [Member] | Actuarial loss [Member]
Summary of accumulated other comprehensive loss
Beginning, balance	(64,369)		(64,789)	(51,822)	(51,508)
Pre-tax Activity	694	518	1,387	1,036
Tax Effect	(273)	(204)	(546)	(408)
Ending, balance	(63,948)	(51,194)	(63,948)	(51,194)	(51,508)
Net pension activity [Member] | Prior service costs [Member]
Summary of accumulated other comprehensive loss
Beginning, balance	(41)		(44)	(43)	(41)
Pre-tax Activity	5	4	10	8
Tax Effect	(2)	(1)	(4)	(3)
Ending, balance	(38)	(38)	(38)	(38)	(41)
Net postretirement benefits activity [Member] | Actuarial loss [Member]
Summary of accumulated other comprehensive loss
Beginning, balance	(20,872)		(21,244)	(17,875)	(17,554)
Pre-tax Activity	612	530	1,225	1,060
Tax Effect	(241)	(209)	(482)	(418)
Ending, balance	(20,501)	(17,233)	(20,501)	(17,233)	(17,554)
Net postretirement benefits activity [Member] | Prior service costs [Member]
Summary of accumulated other comprehensive loss
Beginning, balance	5,021		5,251	6,292	6,032
Pre-tax Activity	(379)	(429)	(758)	(858)
Tax Effect	150	169	299	338
Ending, balance	4,792	5,772	4,792	5,772	6,032
Net postretirement benefits activity [Member] | Transition asset [Member]
Summary of accumulated other comprehensive loss
Beginning, balance				11	8
Pre-tax Activity		(5)		(10)
Tax Effect		2		4
Ending, balance		5		5	8
Foreign currency translation adjustment [Member]
Summary of accumulated other comprehensive loss
Beginning, balance	5		6	4	0
Pre-tax Activity	2	(2)	0	(8)
Tax Effect	(1)	1	0	3
Ending, balance	$ 6	$ (1)	$ 6	$ (1)	$ 0