Employee Retirement Plans - Summary of the Basis Used to Measure Pension Plans' Assets at Fair Value (Details) (USD $) In Thousands, unless otherwise specified	Dec. 28, 2013		Dec. 29, 2012	Dec. 31, 2010
Elgin Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	$ 3,722		$ 3,503	$ 3,188
Smithville Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	9,602		8,781	7,820
Wrexham Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	15,172		12,997	11,518
Total [Member] | Elgin Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	3,722
Total [Member] | Smithville Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	9,602
Total [Member] | Wrexham Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	15,172
Total [Member] | Short Term Investment Fund [Member] | Elgin Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	67	[1]
Total [Member] | Short Term Investment Fund [Member] | Smithville Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	368	[1]
Total [Member] | Short Term Investment Fund [Member] | Wrexham Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	186	[1]
Total [Member] | Equity Securities [Member] | Elgin Plan [Member] | Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	934
Total [Member] | Equity Securities [Member] | Elgin Plan [Member] | Mid Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	100
Total [Member] | Equity Securities [Member] | Elgin Plan [Member] | Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	100
Total [Member] | Equity Securities [Member] | Elgin Plan [Member] | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	942
Total [Member] | Equity Securities [Member] | Smithville Plan [Member] | Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	2,293
Total [Member] | Equity Securities [Member] | Smithville Plan [Member] | Mid Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	254
Total [Member] | Equity Securities [Member] | Smithville Plan [Member] | Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	255
Total [Member] | Equity Securities [Member] | Smithville Plan [Member] | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	2,394
Total [Member] | Equity Securities [Member] | Wrexham Plan [Member] | International Developed Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	4,688
Total [Member] | Equity Securities [Member] | Wrexham Plan [Member] | International Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	589
Total [Member] | Equity Securities [Member] | Wrexham Plan [Member] | International Global Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	733
Total [Member] | Equity Securities [Member] | Wrexham Plan [Member] | United Kingdom [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	5,461
Total [Member] | Fixed Income [Member] | Elgin Plan [Member] | Government/Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	1,030
Total [Member] | Fixed Income [Member] | Elgin Plan [Member] | High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	184
Total [Member] | Fixed Income [Member] | Smithville Plan [Member] | Government/Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	2,647
Total [Member] | Fixed Income [Member] | Smithville Plan [Member] | High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	466
Total [Member] | Fixed Income [Member] | Wrexham Plan [Member] | Government/Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	2,038
Total [Member] | Fixed Income [Member] | Wrexham Plan [Member] | Aggregate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	393
Total [Member] | Fixed Income [Member] | Wrexham Plan [Member] | Index Linked [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	1,084
Total [Member] | Alternative [Member] | Elgin Plan [Member] | Global Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	224
Total [Member] | Alternative [Member] | Elgin Plan [Member] | Commodities Investment [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	141
Total [Member] | Alternative [Member] | Smithville Plan [Member] | Global Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	567
Total [Member] | Alternative [Member] | Smithville Plan [Member] | Commodities Investment [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	358
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Elgin Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	3,655
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Smithville Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	9,234
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Wrexham Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	14,986
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Short Term Investment Fund [Member] | Elgin Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	[1]
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Short Term Investment Fund [Member] | Smithville Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	[1]
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Short Term Investment Fund [Member] | Wrexham Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	[1]
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member] | Elgin Plan [Member] | Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	934
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member] | Elgin Plan [Member] | Mid Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	100
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member] | Elgin Plan [Member] | Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	100
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member] | Elgin Plan [Member] | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	942
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member] | Smithville Plan [Member] | Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	2,293
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member] | Smithville Plan [Member] | Mid Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	254
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member] | Smithville Plan [Member] | Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	255
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member] | Smithville Plan [Member] | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	2,394
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member] | Wrexham Plan [Member] | International Developed Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	4,688
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member] | Wrexham Plan [Member] | International Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	589
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member] | Wrexham Plan [Member] | International Global Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	733
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member] | Wrexham Plan [Member] | United Kingdom [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	5,461
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fixed Income [Member] | Elgin Plan [Member] | Government/Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	1,030
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fixed Income [Member] | Elgin Plan [Member] | High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	184
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fixed Income [Member] | Smithville Plan [Member] | Government/Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	2,647
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fixed Income [Member] | Smithville Plan [Member] | High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	466
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fixed Income [Member] | Wrexham Plan [Member] | Government/Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	2,038
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fixed Income [Member] | Wrexham Plan [Member] | Aggregate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	393
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fixed Income [Member] | Wrexham Plan [Member] | Index Linked [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	1,084
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Alternative [Member] | Elgin Plan [Member] | Global Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	224
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Alternative [Member] | Elgin Plan [Member] | Commodities Investment [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	141
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Alternative [Member] | Smithville Plan [Member] | Global Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	567
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Alternative [Member] | Smithville Plan [Member] | Commodities Investment [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	358
Significant Observable Inputs (Level 2) [Member] | Elgin Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	67
Significant Observable Inputs (Level 2) [Member] | Smithville Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	368
Significant Observable Inputs (Level 2) [Member] | Wrexham Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	186
Significant Observable Inputs (Level 2) [Member] | Short Term Investment Fund [Member] | Elgin Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	67	[1]
Significant Observable Inputs (Level 2) [Member] | Short Term Investment Fund [Member] | Smithville Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	368	[1]
Significant Observable Inputs (Level 2) [Member] | Short Term Investment Fund [Member] | Wrexham Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	186	[1]
Significant Observable Inputs (Level 2) [Member] | Equity Securities [Member] | Elgin Plan [Member] | Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Equity Securities [Member] | Elgin Plan [Member] | Mid Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Equity Securities [Member] | Elgin Plan [Member] | Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Equity Securities [Member] | Elgin Plan [Member] | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Equity Securities [Member] | Smithville Plan [Member] | Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Equity Securities [Member] | Smithville Plan [Member] | Mid Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Equity Securities [Member] | Smithville Plan [Member] | Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Equity Securities [Member] | Smithville Plan [Member] | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Equity Securities [Member] | Wrexham Plan [Member] | International Developed Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Equity Securities [Member] | Wrexham Plan [Member] | International Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Equity Securities [Member] | Wrexham Plan [Member] | International Global Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Equity Securities [Member] | Wrexham Plan [Member] | United Kingdom [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Fixed Income [Member] | Elgin Plan [Member] | Government/Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Fixed Income [Member] | Elgin Plan [Member] | High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Fixed Income [Member] | Smithville Plan [Member] | Government/Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Fixed Income [Member] | Smithville Plan [Member] | High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Fixed Income [Member] | Wrexham Plan [Member] | Government/Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Fixed Income [Member] | Wrexham Plan [Member] | Aggregate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Fixed Income [Member] | Wrexham Plan [Member] | Index Linked [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Alternative [Member] | Elgin Plan [Member] | Global Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Alternative [Member] | Elgin Plan [Member] | Commodities Investment [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Alternative [Member] | Smithville Plan [Member] | Global Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Alternative [Member] | Smithville Plan [Member] | Commodities Investment [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Elgin Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Smithville Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Wrexham Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Short Term Investment Fund [Member] | Elgin Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	[1]
Significant Unobservable Inputs (Level 3) [Member] | Short Term Investment Fund [Member] | Smithville Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	[1]
Significant Unobservable Inputs (Level 3) [Member] | Short Term Investment Fund [Member] | Wrexham Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	[1]
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] | Elgin Plan [Member] | Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] | Elgin Plan [Member] | Mid Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] | Elgin Plan [Member] | Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] | Elgin Plan [Member] | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] | Smithville Plan [Member] | Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] | Smithville Plan [Member] | Mid Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] | Smithville Plan [Member] | Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] | Smithville Plan [Member] | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] | Wrexham Plan [Member] | International Developed Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] | Wrexham Plan [Member] | International Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] | Wrexham Plan [Member] | International Global Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] | Wrexham Plan [Member] | United Kingdom [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Fixed Income [Member] | Elgin Plan [Member] | Government/Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Fixed Income [Member] | Elgin Plan [Member] | High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Fixed Income [Member] | Smithville Plan [Member] | Government/Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Fixed Income [Member] | Smithville Plan [Member] | High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Fixed Income [Member] | Wrexham Plan [Member] | Government/Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Fixed Income [Member] | Wrexham Plan [Member] | Aggregate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Fixed Income [Member] | Wrexham Plan [Member] | Index Linked [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Alternative [Member] | Elgin Plan [Member] | Global Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Alternative [Member] | Elgin Plan [Member] | Commodities Investment [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Alternative [Member] | Smithville Plan [Member] | Global Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Alternative [Member] | Smithville Plan [Member] | Commodities Investment [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	$ 0

[1] Represents collective short term investment fund, composed of high-grade money market instruments with short maturities.