Summary of Significant Accounting Policies Life Insurance Policies (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 28, 2013	Jun. 29, 2012	Jun. 28, 2013	Jun. 29, 2012	Dec. 31, 2012
Life Insurance Policies [Abstract]
Gross cash surrender value of life insurance	$ 25,400,000		$ 25,400,000		$ 24,800,000
Loan on cash surrender value of life insurance	24,300,000		24,300,000		23,100,000
Cash Surrender Value of Life Insurance, Net of Loans	1,100,000		1,100,000		1,700,000
Non-taxable life insurance proceeds	0	423,000	0	423,000
Total death benefit on life insurance contracts	37,200,000		37,200,000
Life insurance proceeds to be received upon death of participants	12,900,000		12,900,000
Life insurance gain to be recognized upon death of participants	$ 11,800,000		$ 11,800,000