Income Taxes (Details) (Summary of Tax Attribute Carryforwards) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 27, 2014
US-net operating loss carryovers | Federal
Tax Attribute Carryforwards [Line Items]
Operating loss carryforwards, amount	$ 5,432
Operating loss carryforwards, limitations on use	Utilization of $17 million of the Company’s U.S. federal net operating loss carryforwards are subject to annual limitations
US-net operating loss carryovers | State/Provincial
Tax Attribute Carryforwards [Line Items]
Operating loss carryforwards, amount	231
US-net operating loss carryovers | From
Tax Attribute Carryforwards [Line Items]
Operating loss carryforwards, expiration dates	Jan. 01, 2015
US-net operating loss carryovers | To
Tax Attribute Carryforwards [Line Items]
Operating loss carryforwards, expiration dates	Dec. 31, 2034
US-credit carryovers | Federal
Tax Attribute Carryforwards [Line Items]
Tax credit carryforward, amount	403
US-credit carryovers | State/Provincial
Tax Attribute Carryforwards [Line Items]
Tax credit carryforward, amount	193
US-credit carryovers | From
Tax Attribute Carryforwards [Line Items]
Tax credit carryforward, expiration date	Jan. 01, 2018
US-credit carryovers | To
Tax Attribute Carryforwards [Line Items]
Tax credit carryforward, expiration date	Dec. 31, 2034
Canada-net operating loss carryovers | Federal
Tax Attribute Carryforwards [Line Items]
Operating loss carryforwards, amount	217
Canada-net operating loss carryovers | State/Provincial
Tax Attribute Carryforwards [Line Items]
Operating loss carryforwards, amount	217
Canada-net operating loss carryovers | From
Tax Attribute Carryforwards [Line Items]
Operating loss carryforwards, expiration dates	Jan. 01, 2025
Canada-net operating loss carryovers | To
Tax Attribute Carryforwards [Line Items]
Operating loss carryforwards, expiration dates	Dec. 31, 2028
Canada-credit carryovers | Federal
Tax Attribute Carryforwards [Line Items]
Tax credit carryforward, amount	357
Canada-credit carryovers | State/Provincial
Tax Attribute Carryforwards [Line Items]
Tax credit carryforward, amount	31
Canada-credit carryovers | From
Tax Attribute Carryforwards [Line Items]
Tax credit carryforward, expiration date	Jan. 01, 2021
Canada-credit carryovers | To
Tax Attribute Carryforwards [Line Items]
Tax credit carryforward, expiration date	Dec. 31, 2034
Canada-R&D pools | Federal
Tax Attribute Carryforwards [Line Items]
Tax credit carryforward, amount	154
Canada-R&D pools | State/Provincial
Tax Attribute Carryforwards [Line Items]
Tax credit carryforward, amount	154
Barbados-net operating loss carryovers | Federal
Tax Attribute Carryforwards [Line Items]
Operating loss carryforwards, amount	198
Barbados-net operating loss carryovers | From
Tax Attribute Carryforwards [Line Items]
Operating loss carryforwards, expiration dates	Jan. 01, 2015
Barbados-net operating loss carryovers | To
Tax Attribute Carryforwards [Line Items]
Operating loss carryforwards, expiration dates	Dec. 31, 2017
Other foreign net operating loss carryovers | Federal
Tax Attribute Carryforwards [Line Items]
Operating loss carryforwards, amount	$ 5