Stockholder Rights Plan (Details) - Junior participating cumulative preferred stock rights	12 Months Ended
	Dec. 29, 2015 item $ / shares shares
Stockholder rights plan
Number of rights per common share	1
Number of shares of junior participating cumulative preferred stock callable by rights | shares	0.01
Rights exercise trigger, minimum percentage of stock acquired or intended to be acquired by an individual or group	15.00%
Rights exercise trigger, minimum percentage of stock acquired or intended to be acquired by a beneficial owner	20.00%
Beneficial ownership interest defined (as a percent)	10.00%
Multiplier of the exercise price that the holder of the rights would receive in value of other than the acquiring company's junior participating cumulative preferred stock	2
Exercise price of junior participating cumulative preferred stock (in dollars per right) | $ / shares	$ 110
Percentage of assets or earning power sold or transferred allowing the rights holder the right to receive common stock of acquiring company	50.00%
Multiplier of the exercise price that the rights holder has right to receive in value of acquiring company's common stock	2