Financial Instruments - Information About Interest Rate Swaps (Details)	Dec. 31, 2016 USD ($) interest_rate_swap	Nov. 30, 2016 EUR (€)	Dec. 31, 2015 USD ($)	Oct. 31, 2014 EUR (€)
Derivative [Line Items]
Par Value of Debt | €		€ 1,000,000,000.0		€ 2,500,000,000.0
Number of Interest Rate Swaps Held | interest_rate_swap	26
U.S. Dollar Notional	$ 25,539,000,000		$ 27,060,000,000
1.30% notes due 2018 | Interest Rate Swap
Derivative [Line Items]
Par Value of Debt	$ 1,000,000,000
Number of Interest Rate Swaps Held | interest_rate_swap	4
U.S. Dollar Notional	$ 1,000,000,000
Fixed-rate notes, stated interest rate (as percent)	1.30%
5.00% notes due 2019 | Interest Rate Swap
Derivative [Line Items]
Par Value of Debt	$ 1,250,000,000
Number of Interest Rate Swaps Held | interest_rate_swap	3
U.S. Dollar Notional	$ 550,000,000
Fixed-rate notes, stated interest rate (as percent)	5.00%
1.85% notes due 2020 | Interest Rate Swap
Derivative [Line Items]
Par Value of Debt	$ 1,250,000,000
Number of Interest Rate Swaps Held | interest_rate_swap	5
U.S. Dollar Notional	$ 1,250,000,000
Fixed-rate notes, stated interest rate (as percent)	1.85%
3.875% notes due 2021 | Interest Rate Swap
Derivative [Line Items]
Par Value of Debt	$ 1,150,000,000
Number of Interest Rate Swaps Held | interest_rate_swap	5
U.S. Dollar Notional	$ 1,150,000,000
Fixed-rate notes, stated interest rate (as percent)	3.875%
2.40% notes due 2022 | Interest Rate Swap
Derivative [Line Items]
Par Value of Debt	$ 1,000,000,000
Number of Interest Rate Swaps Held | interest_rate_swap	4
U.S. Dollar Notional	$ 1,000,000,000
Fixed-rate notes, stated interest rate (as percent)	2.40%
2.35% notes due 2022 | Interest Rate Swap
Derivative [Line Items]
Par Value of Debt	$ 1,250,000,000
Number of Interest Rate Swaps Held | interest_rate_swap	5
U.S. Dollar Notional	$ 1,250,000,000
Fixed-rate notes, stated interest rate (as percent)	2.35%