Long-term debt (Details) (USD $) In Thousands, unless otherwise specified	Jun. 29, 2014	Dec. 29, 2013
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 3,476,142	$ 3,744,067
Debt Instrument, Unamortized Discount (Premium), Net	(23,515)	(31,167)
Long-term Debt	3,452,627	3,712,900
Summary Long-term debt
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	5,890	5,890
Long-term Debt, Excluding Current Maturities	3,446,737	3,707,010
Unsecured Floating Rate Term Loan Due December 2013 Through August 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	139,000	154,800
Unsecured Floating Rate Term Loan Due March 2014 Through December 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	37,145	39,270
Unsecured notes bearing fixed rate interest at 8.75% due November 2014 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	250,000	250,000
Summary Long-term debt
Long-term debt, interest rate, stated percentage	8.75%
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
Long-term debt, 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
Long-term debt, interest rate, stated percentage	6.375%
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
Long-term debt, interest rate, stated percentage	10.00%
Unsecured Fixed Rate Notes 9.375 Percent Due November 2017 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	0	250,000
Summary Long-term debt
Long-term debt, interest rate, stated percentage	9.375%
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
Long-term debt, interest rate, stated percentage	7.125%
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
Long-term debt, interest rate, stated percentage	5.125%
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
Long-term debt, interest rate, stated percentage	5.125%
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
Long-term debt, interest rate, stated percentage	6.375%
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
Long-term debt, 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
Long-term debt, interest rate, stated percentage	7.25%

Amount of long-term debt before deduction of unamortized discount or premium. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, with initial maturities beyond one year or the normal operating cycle, if longer.

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The amount of debt discount (net of debt premium) that was originally recognized at the issuance of the instrument that has yet to be amortized.

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Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates maturing in the next fiscal year following the latest fiscal year.

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