Benefit Plans (Details 8) (USD $) In Thousands, unless otherwise specified	Dec. 30, 2012	Jan. 01, 2012
Pension plan assets measured at fair value on a recurring basis
Total	$ 206,555	$ 168,502
Common/collective trust funds Cash equivalents [Member]
Pension plan assets measured at fair value on a recurring basis
Total	461	453
U.S. large capitalization equity securities [Member]
Pension plan assets measured at fair value on a recurring basis
Total	13,414	10,620
U.S. small/mid-capitalization equity securities [Member]
Pension plan assets measured at fair value on a recurring basis
Total	1,789	2,007
International equity securities [Member]
Pension plan assets measured at fair value on a recurring basis
Total	1,548	1,181
Common/collective trust funds Equity securities [Member]
Pension plan assets measured at fair value on a recurring basis
Total	99,399	79,041
Equity Securities, Other [Member]
Pension plan assets measured at fair value on a recurring basis
Total	606	584
Common/collective trust funds Fixed income [Member]
Pension plan assets measured at fair value on a recurring basis
Total	89,338	74,616
Quoted Prices in Active Market for Identical Assets (Level 1) [Member]
Pension plan assets measured at fair value on a recurring basis
Total	17,357	14,392
Quoted Prices in Active Market for Identical Assets (Level 1) [Member] | Common/collective trust funds Cash equivalents [Member]
Pension plan assets measured at fair value on a recurring basis
Total	0	0
Quoted Prices in Active Market for Identical Assets (Level 1) [Member] | U.S. large capitalization equity securities [Member]
Pension plan assets measured at fair value on a recurring basis
Total	13,414	10,620
Quoted Prices in Active Market for Identical Assets (Level 1) [Member] | U.S. small/mid-capitalization equity securities [Member]
Pension plan assets measured at fair value on a recurring basis
Total	1,789	2,007
Quoted Prices in Active Market for Identical Assets (Level 1) [Member] | International equity securities [Member]
Pension plan assets measured at fair value on a recurring basis
Total	1,548	1,181
Quoted Prices in Active Market for Identical Assets (Level 1) [Member] | Common/collective trust funds Equity securities [Member]
Pension plan assets measured at fair value on a recurring basis
Total	0	0
Quoted Prices in Active Market for Identical Assets (Level 1) [Member] | Equity Securities, Other [Member]
Pension plan assets measured at fair value on a recurring basis
Total	606	584
Quoted Prices in Active Market for Identical Assets (Level 1) [Member] | Common/collective trust funds Fixed income [Member]
Pension plan assets measured at fair value on a recurring basis
Total	0	0
Significant Other Observable Input (Level 2) [Member]
Pension plan assets measured at fair value on a recurring basis
Total	189,198	154,110
Significant Other Observable Input (Level 2) [Member] | Common/collective trust funds Cash equivalents [Member]
Pension plan assets measured at fair value on a recurring basis
Total	461	453
Significant Other Observable Input (Level 2) [Member] | U.S. large capitalization equity securities [Member]
Pension plan assets measured at fair value on a recurring basis
Total	0	0
Significant Other Observable Input (Level 2) [Member] | U.S. small/mid-capitalization equity securities [Member]
Pension plan assets measured at fair value on a recurring basis
Total	0	0
Significant Other Observable Input (Level 2) [Member] | International equity securities [Member]
Pension plan assets measured at fair value on a recurring basis
Total	0	0
Significant Other Observable Input (Level 2) [Member] | Common/collective trust funds Equity securities [Member]
Pension plan assets measured at fair value on a recurring basis
Total	99,399	79,041
Significant Other Observable Input (Level 2) [Member] | Equity Securities, Other [Member]
Pension plan assets measured at fair value on a recurring basis
Total	0	0
Significant Other Observable Input (Level 2) [Member] | Common/collective trust funds Fixed income [Member]
Pension plan assets measured at fair value on a recurring basis
Total	$ 89,338	$ 74,616