CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 27, 2015	Dec. 28, 2014
Accounts receivable, allowances	$ 13,485	$ 12,860
Common stock, par value (USD per share)	$ 0.1	$ 0.1
Class A Common Stock
Authorized shares (in shares)	300,000,000	300,000,000
Issued shares (in shares)	168,263,533	151,701,136
Treasury shares (in shares)	7,691,129	2,180,442
Class B Common Stock
Authorized shares (in shares)	816,635	816,635
Issued shares (in shares)	816,635	816,635
Treasury shares (in shares)	0	0