Schedule of Fair Value of Senior Notes (Parenthetical) (Detail) (Recourse Debt)	6 Months Ended	12 Months Ended
	Jun. 28, 2014	Dec. 28, 2013
Fair Value | 9.75% Senior Secured Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long Term Debt, interest rate	9.75%	9.75%
Fair Value | 7.35% debentures, due 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long Term Debt, interest rate	7.35%	7.35%
Long Term Debt, due date	2016	2016
Fair Value | Revenue bonds, due in varying amounts periodically through 2029
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long Term Debt, due date	2029	2029
Fair Value | American & Foreign Power Company, Inc. 5% debentures, due 2030
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long Term Debt, interest rate	5.00%	5.00%
Long Term Debt, due date	2030	2030
Carrying Value | 9.75% Senior Secured Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long Term Debt, interest rate	9.75%	9.75%
Carrying Value | 7.35% debentures, due 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long Term Debt, interest rate	7.35%	7.35%
Long Term Debt, due date	2016	2016
Carrying Value | Revenue bonds, due in varying amounts periodically through 2029
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long Term Debt, due date	2029	2029
Carrying Value | American & Foreign Power Company, Inc. 5% debentures, due 2030
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long Term Debt, interest rate	5.00%	5.00%
Long Term Debt, due date	2030	2030