Debt (Carrying Value Of Long-term Debt) (Details) (USD $)	Sep. 30, 2013	Jul. 30, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Long-term debt	$ 14,514,100,000		$ 14,727,900,000
Current portion of long-term debt	(100,000)		(557,100,000)
Long-term debt, less current portion	14,514,000,000		14,170,800,000
Capital leases
Debt Instrument [Line Items]
Long-term debt	100,000		300,000
Senior Unsecured Notes | 6.000%, face amount of $400.0, due 2014
Debt Instrument [Line Items]
Debt, interest rate	6.00%
Debt instrument, face amount	400,000,000
Long-term debt	0		399,800,000
Senior Unsecured Notes | 5.000%, face amount of $500.0, due 2014
Debt Instrument [Line Items]
Debt, interest rate	5.00%
Debt instrument, face amount	500,000,000
Long-term debt	527,600,000		535,900,000
Senior Unsecured Notes | 1.250%, face amount of $625.0, due 2015
Debt Instrument [Line Items]
Debt, interest rate	1.25%
Debt instrument, face amount	625,000,000
Long-term debt	624,800,000		624,800,000
Senior Unsecured Notes | 5.250%, face amount of $1,100.0, due 2016
Debt Instrument [Line Items]
Debt, interest rate	5.25%
Debt instrument, face amount	1,100,000,000
Long-term debt	1,109,600,000		1,114,000,000
Senior Unsecured Notes | 2.375%, face amount of $400.0, due 2017
Debt Instrument [Line Items]
Debt, interest rate	2.375%
Debt instrument, face amount	400,000,000
Long-term debt	399,300,000		401,500,000
Senior Unsecured Notes | 5.875%, face amount of $700.0, due 2017
Debt Instrument [Line Items]
Debt, interest rate	5.875%
Debt instrument, face amount	700,000,000
Long-term debt	545,000,000		697,400,000
Senior Unsecured Notes | 1.875%, face amount of $625.0, due 2018
Debt Instrument [Line Items]
Debt, interest rate	1.875%
Debt instrument, face amount	625,000,000
Long-term debt	612,700,000		625,200,000
Senior Unsecured Notes | 2.300%, face amount of $650.0, due 2018
Debt Instrument [Line Items]
Debt, interest rate	2.30%	2.30%
Debt instrument, face amount	650,000,000	650,000,000.0
Long-term debt	647,300,000		0
Senior Unsecured Notes | 7.500%, face amount of $475.0, due 2019
Debt Instrument [Line Items]
Debt, interest rate	7.50%
Debt instrument, face amount	475,000,000
Long-term debt	0		556,900,000
Senior Unsecured Notes | 7.000%, face amount of $600.0, due 2019
Debt Instrument [Line Items]
Debt, interest rate	7.00%
Debt instrument, face amount	600,000,000
Long-term debt	452,800,000		599,300,000
Senior Unsecured Notes | 4.350%, face amount of $700.0, due 2020
Debt Instrument [Line Items]
Debt, interest rate	4.35%
Debt instrument, face amount	700,000,000
Long-term debt	690,800,000		701,000,000
Senior Unsecured Notes | 3.700%, face amount of $700.0, due 2021
Debt Instrument [Line Items]
Debt, interest rate	3.70%
Debt instrument, face amount	700,000,000
Long-term debt	699,300,000		699,300,000
Senior Unsecured Notes | 3.125%, face amount of $850.0, due 2022
Debt Instrument [Line Items]
Debt, interest rate	3.125%
Debt instrument, face amount	850,000,000
Long-term debt	846,200,000		845,900,000
Senior Unsecured Notes | 3.300%, face amount of $1,000.0, due 2023
Debt Instrument [Line Items]
Debt, interest rate	3.30%
Debt instrument, face amount	1,000,000,000
Long-term debt	996,900,000		996,700,000
Senior Unsecured Notes | 5.950%, face amount of $500.0, due 2034
Debt Instrument [Line Items]
Debt, interest rate	5.95%
Debt instrument, face amount	500,000,000
Long-term debt	447,300,000		498,800,000
Senior Unsecured Notes | 5.850%, face amount of $900.0, due 2036
Debt Instrument [Line Items]
Debt, interest rate	5.85%
Debt instrument, face amount	900,000,000
Long-term debt	775,600,000		895,700,000
Senior Unsecured Notes | 6.375%, face amount of $800.0, due 2037
Debt Instrument [Line Items]
Debt, interest rate	6.375%
Debt instrument, face amount	800,000,000
Long-term debt	651,400,000		796,700,000
Senior Unsecured Notes | 5.800%, face amount of $300.0, due 2040
Debt Instrument [Line Items]
Debt, interest rate	5.80%
Debt instrument, face amount	300,000,000
Long-term debt	216,200,000		296,800,000
Senior Unsecured Notes | 4.625%, face amount of $900.0, due 2042
Debt Instrument [Line Items]
Debt, interest rate	4.625%
Debt instrument, face amount	900,000,000
Long-term debt	893,800,000		893,700,000
Senior Unsecured Notes | 4.650%, face amount of $1,000.0, due 2043
Debt Instrument [Line Items]
Debt, interest rate	4.65%
Debt instrument, face amount	1,000,000,000
Long-term debt	994,300,000		994,200,000
Senior Unsecured Notes | 5.100%, face amount of $600.0, due 2044
Debt Instrument [Line Items]
Debt, interest rate	5.10%	5.10%
Debt instrument, face amount	600,000,000	600,000,000.0
Long-term debt	599,200,000		0
Senior Convertible Debentures | 2.750%, face amount of $1,500.0, due 2042
Debt Instrument [Line Items]
Debt, interest rate	2.75%
Debt instrument, face amount	1,500,000,000
Long-term debt	964,000,000		958,100,000
Surplus Notes | 9.000%, face amount of $25.1, due 2027
Debt Instrument [Line Items]
Debt, interest rate	9.00%
Debt instrument, face amount	25,100,000.0
Long-term debt	25,000,000		25,000,000
Commercial Paper
Debt Instrument [Line Items]
Long-term debt	$ 794,900,000		$ 570,900,000