Fair Value Measurements (Schedule of Assets and Liabilities at Fair Value) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 28, 2013	Dec. 31, 2012
Assets
Assets held in rabbi trusts	$ 4,583	$ 4,299
Fair Value, Inputs, Level 1 [Member]
Assets
Assets held in rabbi trusts	1,097	1,102
Fair Value, Inputs, Level 2 [Member]
Assets
Assets held in rabbi trusts	3,486	3,197
Fair Value, Inputs, Level 3 [Member]
Assets
Assets held in rabbi trusts