Consolidated Statements of Comprehensive Earnings (Parenthetical) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 28, 2013	Dec. 29, 2012	Dec. 31, 2011
Statement of Comprehensive Income [Abstract]
Unrealized gain on available-for-sale (AFS) securities, tax effect	$ 41,474	$ 12,567	$ 6,324
Reclassification adjustment for net realized gain on AFS securities, tax effect	(18,458)	(4,013)	(7,684)
Adjustment to postretirement benefit plan obligation, tax effect	$ 7,658	$ (3,498)	$ (3,655)