Accumulated Other Comprehensive Income (Reclassifications out of Accumulated Other Comprehensive Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 28, 2013	Sep. 28, 2013	Jun. 29, 2013	Mar. 30, 2013	Dec. 29, 2012	Sep. 29, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 28, 2013	Dec. 29, 2012	Dec. 31, 2011
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Investment income									$ 4,684	$ 3,468	$ 3,326
Provision for income taxes									(44,145)	(48,403)	(42,022)
Total amount reclassified, net of tax	15,721	11,692	24,179	20,129	22,103	17,178	23,204	20,026	71,721	82,511	75,584
Accumulated Net Unrealized Investment Gain (Loss) [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Investment income									1,774	713	1,447
Provision for income taxes									(730)	(293)	(601)
Total amount reclassified, net of tax									$ 1,044	$ 420	$ 846