Pensions (Details) - USD ($) | 12 Months Ended |
Sep. 25, 2016 | Sep. 27, 2015 | Sep. 28, 2014 | Sep. 29, 2013 |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value | | $ 8,881,000 | $ 8,351,000 | |
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases | | 0 | | |
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Period Increase (Decrease) | | 530,000 | | |
Pension Plans, Defined Benefit [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months | | $ 12,000 | | |
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate | | 4.00% | 5.00% | 4.00% |
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate | | 4.00% | 4.00% | |
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Gain (Loss), before Tax | $ 2,396,000 | $ (48,031,000) | $ (42,348,000) | |
Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent | | 50,463,000 | 48,184,000 | |
Defined Benefit Plan, Benefit Obligation | | 193,751,000 | 199,197,000 | $ 175,771,000 |
Defined Benefit Plan, Accumulated Benefit Obligation | | | 199,197,000 | |
Defined Benefit Plan, Service Cost | | 232,000 | 156,000 | 216,000 |
Defined Benefit Plan, Interest Cost | | 8,122,000 | 7,996,000 | 7,529,000 |
Defined Benefit Plan, Actuarial Gain (Loss) | | (2,543,000) | 26,526,000 | |
Defined Benefit Plan, Benefits Paid | | (11,257,000) | (11,252,000) | |
Defined Benefit Plan, Administration Expenses | | (1,862,000) | (1,509,000) | |
Defined Benefit Plan, Contributions by Employer | 5,782,000 | 3,577,000 | 1,435,000 | |
Defined Benefit Plan, Expected Return on Plan Assets | | (9,863,000) | (9,932,000) | (9,838,000) |
Defined Benefit Plan, Amortization of Net Gains (Losses) | | (1,682,000) | 423,000 | 2,287,000 |
Defined Benefit Plan, Amortization of Net Prior Service Cost (Credit) | | (136,000) | (136,000) | (136,000) |
Defined Benefit Plan, Net Periodic Benefit Cost | | 37,000 | (1,493,000) | 58,000 |
Defined Benefit Plan, Fair Value of Plan Assets | | 143,288,000 | 151,013,000 | $ 147,265,000 |
Defined Benefit Plan, Actual Return on Plan Assets | | 1,817,000 | 15,074,000 | |
Defined Benefit Plan, Funded Status of Plan | | 50,463,000 | 48,184,000 | |
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax | | (47,515,000) | (41,695,000) | |
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Prior Service Cost, before Tax | $ (137,000) | 516,000 | 653,000 | |
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Tax | | $ (47,515,000) | $ (41,695,000) | |
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Return on Assets | 0.00% | 7.00% | 7.00% | 8.00% |
Defined Benefit Plan, Expected Future Benefit Payments, Year Two | | $ 12,000 | | |
Defined Benefit Plan, Expected Future Benefit Payments, Year Three | | 12,000 | | |
Defined Benefit Plan, Expected Future Benefit Payments, Year Four | | 12,000 | | |
Defined Benefit Plan, Expected Future Benefit Payments, Year Five | | 12,000 | | |
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter | | 59,000 | | |
Change in PBO due to new mortality tables | | $ 18,515,000 | | |
Pension Plans, Defined Benefit [Member] | Equity Securities [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Actual Plan Asset Allocations | | 46.00% | 48.00% | |
Defined Benefit Plan, Target Plan Asset Allocations | | 5000.00% | | |
Pension Plans, Defined Benefit [Member] | Fixed Income Securities [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Actual Plan Asset Allocations | | 37.00% | 20.00% | |
Defined Benefit Plan, Target Plan Asset Allocations | | 3500.00% | | |
Pension Plans, Defined Benefit [Member] | Fixed Income Securities [Member] | Fair Value, Inputs, Level 1 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | $ 31,195,592 | | |
Pension Plans, Defined Benefit [Member] | Fixed Income Securities [Member] | Fair Value, Inputs, Level 2 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | 21,370,261 | | |
Pension Plans, Defined Benefit [Member] | Fixed Income Securities [Member] | Fair Value, Inputs, Level 3 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | $ 0 | | |
Pension Plans, Defined Benefit [Member] | US Treasury Securities [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Actual Plan Asset Allocations | | 4.00% | 4.00% | |
Defined Benefit Plan, Target Plan Asset Allocations | | 500.00% | | |
Pension Plans, Defined Benefit [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | $ 6,450,421 | | |
Pension Plans, Defined Benefit [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | 0 | | |
Pension Plans, Defined Benefit [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 3 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | $ 0 | | |
Pension Plans, Defined Benefit [Member] | Hedge Funds [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Actual Plan Asset Allocations | | 11.00% | 10.00% | |
Defined Benefit Plan, Target Plan Asset Allocations | | 1000.00% | | |
Pension Plans, Defined Benefit [Member] | Hedge Funds [Member] | Fair Value, Inputs, Level 1 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | $ 0 | | |
Pension Plans, Defined Benefit [Member] | Hedge Funds [Member] | Fair Value, Inputs, Level 2 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | 8,463,283 | | |
Pension Plans, Defined Benefit [Member] | Hedge Funds [Member] | Fair Value, Inputs, Level 3 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | $ 8,881,433 | | |
Pension Plans, Defined Benefit [Member] | Cash and Cash Equivalents [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Actual Plan Asset Allocations | | 2.00% | 18.00% | |
Defined Benefit Plan, Target Plan Asset Allocations | | 0.00% | | |
Pension Plans, Defined Benefit [Member] | Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | $ 2,407,063 | | |
Pension Plans, Defined Benefit [Member] | Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | 0 | | |
Pension Plans, Defined Benefit [Member] | Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | 0 | | |
Other Postretirement Benefit Plans, Defined Benefit [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months | | $ 3,320,000 | | |
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate | | 4.00% | 4.00% | 4.00% |
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate | | 4.00% | 4.00% | |
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Gain (Loss), before Tax | | $ 13,155,000 | $ 16,394,000 | |
Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent | | 7,109,000 | 6,761,000 | |
Defined Benefit Plan, Benefit Obligation | | 23,812,000 | 25,506,000 | $ 23,432,000 |
Defined Benefit Plan, Service Cost | | 76,000 | 596,000 | 1,000 |
Defined Benefit Plan, Interest Cost | | 922,000 | 911,000 | 1,000 |
Defined Benefit Plan, Actuarial Gain (Loss) | | (1,149,000) | 2,298,000 | |
Defined Benefit Plan, Benefits Paid | | (1,541,000) | (1,905,000) | |
Defined Benefit Plan, Contributions by Employer | | 745,000 | 597,000 | |
Defined Benefit Plan, Expected Return on Plan Assets | | (1,445,000) | (1,483,000) | (1,000) |
Defined Benefit Plan, Amortization of Net Gains (Losses) | | 1,386,000 | (1,819,000) | (1,000) |
Defined Benefit Plan, Amortization of Net Prior Service Cost (Credit) | | (1,459,000) | (1,459,000) | (1,000) |
Defined Benefit Plan, Net Periodic Benefit Cost | | (3,292,000) | (3,254,000) | (2,000) |
Defined Benefit Plan, Fair Value of Plan Assets | | 30,123,000 | 32,881,000 | $ 33,920,000 |
Defined Benefit Plan, Actual Return on Plan Assets | | (547,000) | 1,167,000 | |
Defined Benefit Plan, Funded Status of Plan | | (6,311,000) | (7,375,000) | |
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax | | 22,551,000 | 27,250,000 | |
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Prior Service Cost, before Tax | | 9,396,000 | 10,856,000 | |
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Tax | | $ 22,551,000 | $ 27,250,000 | |
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Return on Assets | | 5.00% | 5.00% | 5.00% |
Defined Benefit Plan, Expected Future Benefit Payments, Year Two | | $ 2,130,000 | | |
Defined Benefit Plan, Expected Future Benefit Payments, Year Three | | 2,040,000 | | |
Defined Benefit Plan, Expected Future Benefit Payments, Year Four | | 2,070,000 | | |
Defined Benefit Plan, Expected Future Benefit Payments, Year Five | | 2,040,000 | | |
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter | | $ 9,180,000 | | |
Other Postretirement Benefit Plans, Defined Benefit [Member] | Equity Securities [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Actual Plan Asset Allocations | | 0.00% | 0.00% | |
Defined Benefit Plan, Target Plan Asset Allocations | | 2000.00% | | |
Other Postretirement Benefit Plans, Defined Benefit [Member] | Fixed Income Securities [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Actual Plan Asset Allocations | | 100.00% | 100.00% | |
Defined Benefit Plan, Target Plan Asset Allocations | | 7000.00% | | |
Other Postretirement Benefit Plans, Defined Benefit [Member] | Fixed Income Securities [Member] | Fair Value, Inputs, Level 1 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | | $ 13,910,089 | |
Other Postretirement Benefit Plans, Defined Benefit [Member] | Fixed Income Securities [Member] | Fair Value, Inputs, Level 2 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | | 6,581,087 | |
Other Postretirement Benefit Plans, Defined Benefit [Member] | Fixed Income Securities [Member] | Fair Value, Inputs, Level 3 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | | 0 | |
Other Postretirement Benefit Plans, Defined Benefit [Member] | Hedge Funds [Member] | Fair Value, Inputs, Level 1 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | | 0 | |
Other Postretirement Benefit Plans, Defined Benefit [Member] | Hedge Funds [Member] | Fair Value, Inputs, Level 2 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | | 3,072,410 | |
Other Postretirement Benefit Plans, Defined Benefit [Member] | Hedge Funds [Member] | Fair Value, Inputs, Level 3 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | | $ 0 | |
Other Postretirement Benefit Plans, Defined Benefit [Member] | Cash and Cash Equivalents [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Actual Plan Asset Allocations | | 0.00% | 0.00% | |
Defined Benefit Plan, Target Plan Asset Allocations | | 0.00% | | |
Other Postretirement Benefit Plans, Defined Benefit [Member] | Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | | $ 790,112 | |
Other Postretirement Benefit Plans, Defined Benefit [Member] | Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | | 0 | |
Other Postretirement Benefit Plans, Defined Benefit [Member] | Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | | 0 | |
Other Plans [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Funded Status of Plan | | $ 2,337,000 | 2,264,000 | |
Funded Status of Other Plans Recognized In Other Liabilities | | 279,000 | | |
Domestic Equity Securities [Member] | Pension Plans, Defined Benefit [Member] | Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | 8,153,243 | | |
Domestic Equity Securities [Member] | Pension Plans, Defined Benefit [Member] | Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | 44,470,336 | | |
Domestic Equity Securities [Member] | Pension Plans, Defined Benefit [Member] | Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | 0 | | |
Domestic Equity Securities [Member] | Other Postretirement Benefit Plans, Defined Benefit [Member] | Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | | 2,895,969 | |
Domestic Equity Securities [Member] | Other Postretirement Benefit Plans, Defined Benefit [Member] | Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | | 1,371,502 | |
Domestic Equity Securities [Member] | Other Postretirement Benefit Plans, Defined Benefit [Member] | Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | | 0 | |
International Equity Securities [Member] | Pension Plans, Defined Benefit [Member] | Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | 6,286,382 | | |
International Equity Securities [Member] | Pension Plans, Defined Benefit [Member] | Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | 7,389,381 | | |
International Equity Securities [Member] | Pension Plans, Defined Benefit [Member] | Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | $ 0 | | |
International Equity Securities [Member] | Other Postretirement Benefit Plans, Defined Benefit [Member] | Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | | 645,192 | |
International Equity Securities [Member] | Other Postretirement Benefit Plans, Defined Benefit [Member] | Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | | 857,424 | |
International Equity Securities [Member] | Other Postretirement Benefit Plans, Defined Benefit [Member] | Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member] | | | | |
Defined Benefit Plan Disclosure [Line Items] | | | | |
Defined Benefit Plan, Fair Value of Plan Assets | | | $ 0 | |