Other Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Apr. 01, 2012
Changes in Accumulated Other Comprehensive Income
Accumulated other comprehensive income, Cumulative translation adjustment, Beginning balance	$ 1,219
Accumulated other comprehensive income, Defined benefit pension items, Beginning balance	(120,843)
Accumulated other comprehensive income, Unrealized gains and losses on cash flow hedges, Beginning balance	(980)
Accumulated other comprehensive income, Beginning balance	(120,604)
Other comprehensive earnings before reclassifications, Cumulative translation adjustment	(1,714)
Other comprehensive earnings before reclassifications, Defined benefit pension items
Other comprehensive earnings before reclassifications, Unrealized gains and losses on cash flow hedges	22
Other comprehensive earnings before reclassifications, Total	(1,719)
Amounts reclassified from accumulated other comprehensive income , Cumulative translation adjustment	0
Amounts reclassified from accumulated other comprehensive income, Defined benefit pension items	1,543	958
Amounts reclassified from accumulated other comprehensive income, Unrealized gains and losses on cash flow hedges	47
Amounts reclassified from accumulated other comprehensive income, Total	1,590
Net current period other comprehensive income, Cumulative translation adjustment	(1,741)	1,162
Subtotal-net reclassification to earnings-defined benefit and post-retirement benefit plans	1,543
Net change in unrealized holding loss on interest rate swaps	69
Other comprehensive (loss)/earnings	(129)	2,120
Accumulated other comprehensive income, Cumulative translation adjustment, Ending balance	(522)
Accumulated other comprehensive income, Unrealized gains and losses on cash flow hedges, Ending balance	(911)
Accumulated other comprehensive income, Defined benefit pension item, Ending balance	(119,300)
Accumulated other comprehensive income, Ending balance	$ (120,733)