Long-term debt (Details) (USD $) | Mar. 29, 2015 | Dec. 28, 2014 |
In Thousands, unless otherwise specified |
Debt Instrument [Line Items] | | |
Long-term Debt, Gross | $4,381,551 | $4,521,576 |
Debt Instrument, Unamortized Discount (Premium), Net | -22,149 | -25,694 |
Long-term Debt | 4,359,402 | 4,495,882 |
Current portion of long-term debt | 7,854 | 7,854 |
Summary Long-term debt | | |
Long-term Debt, Excluding Current Maturities | 4,351,548 | 4,488,028 |
Unsecured Floating Rate Term Loan Due Quarterly Through August 2018 [Member] | | |
Debt Instrument [Line Items] | | |
Debt Instrument, Face Amount | 115,300 | 123,200 |
Unsecured Floating Rate Term Loan Due Quarterly Through December 2018 [Member] | | |
Debt Instrument [Line Items] | | |
Debt Instrument, Face Amount | 31,254 | 33,379 |
Unsecured notes bearing fixed rate interest at 10% due June 2015 [Member] | | |
Debt Instrument [Line Items] | | |
Debt Instrument, Face Amount | 66,568 | 66,568 |
Summary Long-term debt | | |
Debt Instrument, Interest Rate, Stated Percentage | 10.00% | |
Unsecured notes bearing fixed rate interest at 6.375% due September 2015 [Member] | | |
Debt Instrument [Line Items] | | |
Debt Instrument, Face Amount | 250,000 | 250,000 |
Summary Long-term debt | | |
Debt Instrument, Interest Rate, Stated Percentage | 6.38% | |
Unsecured notes bearing fixed rate interest at 10% due April 2016 [Member] | | |
Debt Instrument [Line Items] | | |
Debt Instrument, Face Amount | 193,429 | 193,429 |
Summary Long-term debt | | |
Debt Instrument, Interest Rate, Stated Percentage | 10.00% | |
Revolving Credit Agreements Expiring August 2018 [Member] | | |
Debt Instrument [Line Items] | | |
Debt Instrument, Face Amount | 510,000 | 640,000 |
Unsecured notes bearing fixed rate interest at 7.125% due September 2018 [Member] | | |
Debt Instrument [Line Items] | | |
Debt Instrument, Face Amount | 250,000 | 250,000 |
Summary Long-term debt | | |
Debt Instrument, Interest Rate, Stated Percentage | 7.13% | |
Unsecured Fixed Rate Notes 5.125 Percent Due October 2019 [Member] | | |
Debt Instrument [Line Items] | | |
Debt Instrument, Face Amount | 600,000 | 600,000 |
Summary Long-term debt | | |
Debt Instrument, Interest Rate, Stated Percentage | 5.13% | |
Unsecured Fixed Rate Notes 5.125 Percent Due July 2020 [Member] | | |
Debt Instrument [Line Items] | | |
Debt Instrument, Face Amount | 600,000 | 600,000 |
Summary Long-term debt | | |
Debt Instrument, Interest Rate, Stated Percentage | 5.13% | |
Unsecured Fixed Rate Notes 4.875 Percent Due September 2021 [Member] | | |
Debt Instrument [Line Items] | | |
Debt Instrument, Face Amount | 350,000 | 350,000 |
Summary Long-term debt | | |
Debt Instrument, Interest Rate, Stated Percentage | 4.88% | |
Unsecured Fixed Rate Notes 6.375 Percent Due October 2023 [Member] | | |
Debt Instrument [Line Items] | | |
Debt Instrument, Face Amount | 650,000 | 650,000 |
Summary Long-term debt | | |
Debt Instrument, Interest Rate, Stated Percentage | 6.38% | |
Unsecured Fixed Rate Notes 5.500 Percent Due September 2024 [Member] | | |
Debt Instrument [Line Items] | | |
Debt Instrument, Face Amount | 325,000 | 325,000 |
Summary Long-term debt | | |
Debt Instrument, Interest Rate, Stated Percentage | 5.50% | |
Unsecured Fixed Rate Notes 7.75 Percent Due June 2027 [Member] | | |
Debt Instrument [Line Items] | | |
Debt Instrument, Face Amount | 200,000 | 200,000 |
Summary Long-term debt | | |
Debt Instrument, Interest Rate, Stated Percentage | 7.75% | |
Unsecured Fixed Rate Notes 7.25 Percent Due September 2027 [Member] | | |
Debt Instrument [Line Items] | | |
Debt Instrument, Face Amount | $240,000 | $240,000 |
Summary Long-term debt | | |
Debt Instrument, Interest Rate, Stated Percentage | 7.25% | |