Employee Benefit Plans (Schedule of Effect of Significant Unobservable Inputs, Changes in Plan Assets, Pension Plans) (Details) (Pension Plans, Defined Benefit, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	$ 413,021	$ 393,460
Venture Capital Funds [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	1	8
Multi-strategy hedge funds [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	23,332	22,689
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	22,697	20,431	19,292
Realized gains (losses)	0	7	1,162
Unrealized gains (losses)	636	2,409	996
Fair value of plan assets at end of year	23,333	22,697	20,431
Fair Value, Inputs, Level 3 [Member] | Common Collective Trusts [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	0	162	0
Realized gains (losses)	0	7	1,162
Unrealized gains (losses)	0	(19)	19
Fair value of plan assets at end of year	0	0	162
Fair Value, Inputs, Level 3 [Member] | Venture Capital Funds [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	8	7	7
Realized gains (losses)	0	0	0
Unrealized gains (losses)	(7)	1	0
Fair value of plan assets at end of year	1	8	7
Fair Value, Inputs, Level 3 [Member] | Multi-strategy hedge funds [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	22,689	20,262	19,285
Realized gains (losses)	0	0	0
Unrealized gains (losses)	643	2,427	977
Fair value of plan assets at end of year	23,332	22,689	20,262
Defined Benefit Plan, Purchases [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Purchases, issuances, and settlements	0		9,448
Defined Benefit Plan, Purchases [Member] | Fair Value, Inputs, Level 3 [Member] | Common Collective Trusts [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Purchases, issuances, and settlements	0		9,448
Defined Benefit Plan, Purchases [Member] | Fair Value, Inputs, Level 3 [Member] | Venture Capital Funds [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Purchases, issuances, and settlements	0		0
Defined Benefit Plan, Purchases [Member] | Fair Value, Inputs, Level 3 [Member] | Multi-strategy hedge funds [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Purchases, issuances, and settlements	0		0
Defined Benefit Plans, Sales and Settlements [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Purchases, issuances, and settlements	0	(150)	(10,467)
Defined Benefit Plans, Sales and Settlements [Member] | Fair Value, Inputs, Level 3 [Member] | Common Collective Trusts [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Purchases, issuances, and settlements	0	150	10,467
Defined Benefit Plans, Sales and Settlements [Member] | Fair Value, Inputs, Level 3 [Member] | Venture Capital Funds [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Purchases, issuances, and settlements	0	0	0
Defined Benefit Plans, Sales and Settlements [Member] | Fair Value, Inputs, Level 3 [Member] | Multi-strategy hedge funds [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Purchases, issuances, and settlements	$ 0	$ 0	$ 0