Net Periodic Benefit Cost - Defined Benefit Pension Plans (Details) (Pension plans, defined benefit [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jul. 02, 2011	Jun. 30, 2012	Jul. 02, 2011
Pension plans, defined benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service costs--increase in benefit obligation earned	$ 47	$ 34	$ 91	$ 67
Interest cost on projected benefit obligation	415	417	832	835
Expected return on plan assets	(425)	(477)	(853)	(954)
Settlement loss	219	0	219	0
Amortization of net actuarial loss	260	133	522	267
Amortization of prior service cost	4	4	7	7
Amortization of transition asset	0	(17)	0	(34)
Net pension cost of defined benefit pension plans	520	94	818	188
Contributions by employer			428
Estimated future employer contributions in current fiscal year	$ 582		$ 582