Debt - Narrative (Details)	1 Months Ended			6 Months Ended
	May. 31, 2015 USD ($)	Mar. 31, 2015 EUR (€)	Feb. 28, 2015 USD ($)	Jul. 04, 2015 USD ($)	Apr. 04, 2015 USD ($)	Jan. 03, 2015 USD ($)
Debt Instrument [Line Items]
Notional amounts of interest rate swaps				$ 3,703,000,000		$ 4,214,000,000
Notes Payable, Other Payables | Terminated Interest Rate Swap
Debt Instrument [Line Items]
Unrealized gain gain on termination of interest rate fair value hedge					$ 26,000,000
Notes Payable, Other Payables | Fair Value Hedges | Interest Rate Swap
Debt Instrument [Line Items]
Notional amounts of interest rate swaps				2,400,000,000
Notes Payable, Other Payables | Fair Value Hedges | First Quarter 2015 Interest Rate Swaps
Debt Instrument [Line Items]
Notional amounts of interest rate swaps					558,000,000
Notes Payable, Other Payables | Fair Value Hedges | Second Quarter 2015 Interest Rate Swaps
Debt Instrument [Line Items]
Notional amounts of interest rate swaps				958,000,000
Notes Payable, Other Payables | Fair Value Hedges | Terminated Interest Rate Swap | Interest Rate Swap
Debt Instrument [Line Items]
Notional amounts of interest rate swaps					1,500,000,000
Notes Payable, Other Payables | 1.125% Fixed Rate U.S. Dollar Notes Due 2015
Debt Instrument [Line Items]
Debt repaid	$ 350,000,000
Debt instrument, stated interest rate	1.125%
Notes Payable, Other Payables | Floating Rate U.S. Dollar Notes Due 2015
Debt Instrument [Line Items]
Debt repaid			$ 250,000,000
Notes Payable, Other Payables | 1.25% Euro Notes Due 2025
Debt Instrument [Line Items]
Debt instrument, face amount		€ 600,000,000		$ 665,000,000
Debt instrument term		10 years
Debt instrument, stated interest rate		1.25%
Notes Payable, Other Payables | 4.15% U.S. Dollar Notes Due 2019
Debt Instrument [Line Items]
Debt instrument term				10 years
Debt instrument, stated interest rate				4.15%
Effective interest rate				2.58%
Notes Payable, Other Payables | 4.15% U.S. Dollar Notes Due 2019 | First Quarter 2015 Interest Rate Swaps
Debt Instrument [Line Items]
Debt instrument, face amount					$ 300,000,000
Debt instrument, stated interest rate					4.15%
Notes Payable, Other Payables | 4.15% U.S. Dollar Notes Due 2019 | Second Quarter 2015 Interest Rate Swaps
Debt Instrument [Line Items]
Debt instrument, face amount				$ 500,000,000
Debt instrument, stated interest rate				4.15%
Notes Payable, Other Payables | 4.15% U.S. Dollar Notes Due 2019 | Terminated Interest Rate Swap
Debt Instrument [Line Items]
Debt instrument, face amount					$ 800,000,000
Debt instrument, stated interest rate					4.15%
Notes Payable, Other Payables | 4.0% U.S. Dollar Notes Due 2020
Debt Instrument [Line Items]
Debt instrument term				10 years
Debt instrument, stated interest rate				4.00%
Effective interest rate				1.52%
Notes Payable, Other Payables | 4.0% U.S. Dollar Notes Due 2020 | First Quarter 2015 Interest Rate Swaps
Debt Instrument [Line Items]
Debt instrument, face amount					$ 200,000,000
Debt instrument, stated interest rate					4.00%
Notes Payable, Other Payables | 4.0% U.S. Dollar Notes Due 2020 | Second Quarter 2015 Interest Rate Swaps
Debt Instrument [Line Items]
Debt instrument, face amount				$ 300,000,000
Debt instrument, stated interest rate				4.00%
Notes Payable, Other Payables | 4.0% U.S. Dollar Notes Due 2020 | Terminated Interest Rate Swap
Debt Instrument [Line Items]
Debt instrument, face amount					$ 500,000,000
Debt instrument, stated interest rate					4.00%
Notes Payable, Other Payables | 3.125% U.S. Dollar Notes Due 2022
Debt Instrument [Line Items]
Debt instrument term				10 years
Debt instrument, stated interest rate				3.125%
Effective interest rate				1.44%
Notes Payable, Other Payables | 3.125% U.S. Dollar Notes Due 2022 | First Quarter 2015 Interest Rate Swaps
Debt Instrument [Line Items]
Debt instrument, face amount					$ 58,000,000
Debt instrument, stated interest rate					3.125%
Notes Payable, Other Payables | 3.125% U.S. Dollar Notes Due 2022 | Second Quarter 2015 Interest Rate Swaps
Debt Instrument [Line Items]
Debt instrument, face amount				$ 158,000,000
Debt instrument, stated interest rate				3.125%
Notes Payable, Other Payables | 3.125% U.S. Dollar Notes Due 2022 | Terminated Interest Rate Swap
Debt Instrument [Line Items]
Debt instrument, face amount					$ 216,000,000
Debt instrument, stated interest rate					3.125%
Notes Payable, Other Payables | 4.45% U.S. Dollar Notes Due 2016
Debt Instrument [Line Items]
Debt instrument term				7 years
Debt instrument, stated interest rate				4.45%
Effective interest rate				3.58%
Notes Payable, Other Payables | 1.875% U.S. Dollar Notes Due 2016
Debt Instrument [Line Items]
Debt instrument term				5 years
Debt instrument, stated interest rate				1.875%
Effective interest rate				1.58%
Notes Payable, Other Payables | 1.75% U.S. Dollar Notes Due 2017
Debt Instrument [Line Items]
Debt instrument term				5 years
Debt instrument, stated interest rate				1.75%
Effective interest rate				1.36%
Notes Payable, Other Payables | 3.25% U.S. Dollar Notes Due 2018
Debt Instrument [Line Items]
Debt instrument term				7 years
Debt instrument, stated interest rate				3.25%
Effective interest rate				1.88%