Per Share Amounts and Common Shares Outstanding stock subscription (Details) (USD $)	3 Months Ended	9 Months Ended
	Sep. 29, 2012 Rate	Sep. 29, 2012 Rate
Per Share Amounts and Common Shares Outstanding [Abstract]
Stock subscription offering, subscription price	$ 19.70	$ 19.70
Stock subscription offering, number of shares subscribed	637,714
stock subscription offering, value of shares subscribed	$ 12,563,000
Stock subscription offering, minimum financed amount	5,000	5,000
Stock subscription offering, down payment	10.00%	10.00%
Stock subscription offering, term (in years)		7 years
Stock subscription offering interest rate		2.00%
Stock subscription offering, minimum amount to receive right	$ 5,000	$ 5,000
Stock subscription offering, number of shares purchased to receive one right		3
Stock subscription offering, number of rights issued	211,800
Stock subscription offering, right expiration term (in years)		P7Y
Stock subscription offering, portion exercisable per year		14.29%