Financial Instruments (Details) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended					3 Months Ended
	Mar. 31, 2014 USD ($)	Mar. 31, 2013 USD ($)	Dec. 31, 2013 USD ($)	Mar. 31, 2014 Due 2019 [Member]	Feb. 28, 2014 Due 2019 [Member] USD ($)	Mar. 31, 2014 Due 2044 [Member]	Feb. 28, 2014 Due 2044 [Member] USD ($)	Mar. 31, 2014 Equity Contract [Member] USD ($)	Mar. 31, 2013 Equity Contract [Member] USD ($)	Mar. 31, 2014 Hedged Fixed-Rate Debt [Member] USD ($)	Mar. 31, 2013 Hedged Fixed-Rate Debt [Member] USD ($)	Mar. 31, 2014 Interest Rate Contract [Member] USD ($)	Mar. 31, 2013 Interest Rate Contract [Member] USD ($)	Mar. 31, 2014 Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2013 Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Mar. 31, 2014 Carrying (Reported) Amount, Fair Value Disclosure [Member] Equity Contract [Member] USD ($)	Dec. 31, 2013 Carrying (Reported) Amount, Fair Value Disclosure [Member] Equity Contract [Member] USD ($)	Mar. 31, 2014 Carrying (Reported) Amount, Fair Value Disclosure [Member] Interest Rate Contract [Member] USD ($)	Dec. 31, 2013 Carrying (Reported) Amount, Fair Value Disclosure [Member] Interest Rate Contract [Member] USD ($)	Mar. 31, 2014 Carrying (Reported) Amount, Fair Value Disclosure [Member] Foreign Exchange Contract [Member] USD ($)	Dec. 31, 2013 Carrying (Reported) Amount, Fair Value Disclosure [Member] Foreign Exchange Contract [Member] USD ($)	Mar. 31, 2014 Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Dec. 31, 2013 Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Mar. 31, 2014 Fair Value, Inputs, Level 1 [Member] USD ($)	Dec. 31, 2013 Fair Value, Inputs, Level 1 [Member] USD ($)	Mar. 31, 2014 Fair Value, Inputs, Level 2 [Member] USD ($)	Dec. 31, 2013 Fair Value, Inputs, Level 2 [Member] USD ($)	Mar. 31, 2014 Fair Value, Inputs, Level 2 [Member] Equity Contract [Member] USD ($)	Dec. 31, 2013 Fair Value, Inputs, Level 2 [Member] Equity Contract [Member] USD ($)	Mar. 31, 2014 Fair Value, Inputs, Level 2 [Member] Interest Rate Contract [Member] USD ($)	Dec. 31, 2013 Fair Value, Inputs, Level 2 [Member] Interest Rate Contract [Member] USD ($)	Mar. 31, 2014 Fair Value, Inputs, Level 2 [Member] Foreign Exchange Contract [Member] USD ($)	Dec. 31, 2013 Fair Value, Inputs, Level 2 [Member] Foreign Exchange Contract [Member] USD ($)	Mar. 31, 2014 Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2013 Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Mar. 31, 2014 Estimate of Fair Value, Fair Value Disclosure [Member] Equity Contract [Member] USD ($)	Dec. 31, 2013 Estimate of Fair Value, Fair Value Disclosure [Member] Equity Contract [Member] USD ($)	Mar. 31, 2014 Estimate of Fair Value, Fair Value Disclosure [Member] Interest Rate Contract [Member] USD ($)	Dec. 31, 2013 Estimate of Fair Value, Fair Value Disclosure [Member] Interest Rate Contract [Member] USD ($)	Mar. 31, 2014 Estimate of Fair Value, Fair Value Disclosure [Member] Foreign Exchange Contract [Member] USD ($)	Dec. 31, 2013 Estimate of Fair Value, Fair Value Disclosure [Member] Foreign Exchange Contract [Member] USD ($)	Mar. 31, 2014 Corporate Debt Securities [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2013 Corporate Debt Securities [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Mar. 31, 2014 Corporate Debt Securities [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Dec. 31, 2013 Corporate Debt Securities [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Mar. 31, 2014 Corporate Debt Securities [Member] Fair Value, Inputs, Level 2 [Member] USD ($)	Dec. 31, 2013 Corporate Debt Securities [Member] Fair Value, Inputs, Level 2 [Member] USD ($)	Mar. 31, 2014 Corporate Debt Securities [Member] Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2013 Corporate Debt Securities [Member] Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Mar. 31, 2014 US Government Agencies Debt Securities [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2013 US Government Agencies Debt Securities [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Mar. 31, 2014 US Government Agencies Debt Securities [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Dec. 31, 2013 US Government Agencies Debt Securities [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Mar. 31, 2014 US Government Agencies Debt Securities [Member] Fair Value, Inputs, Level 1 [Member] USD ($)	Dec. 31, 2013 US Government Agencies Debt Securities [Member] Fair Value, Inputs, Level 1 [Member] USD ($)	Mar. 31, 2014 US Government Agencies Debt Securities [Member] Fair Value, Inputs, Level 2 [Member] USD ($)	Dec. 31, 2013 US Government Agencies Debt Securities [Member] Fair Value, Inputs, Level 2 [Member] USD ($)	Mar. 31, 2014 US Government Agencies Debt Securities [Member] Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2013 US Government Agencies Debt Securities [Member] Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Mar. 31, 2014 Foreign Government Debt Securities [Member] USD ($)	Mar. 31, 2014 Foreign Government Debt Securities [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Mar. 31, 2014 Foreign Government Debt Securities [Member] Fair Value, Inputs, Level 2 [Member] USD ($)	Mar. 31, 2014 Foreign Government Debt Securities [Member] Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Mar. 31, 2014 Other Debt Obligations [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2013 Other Debt Obligations [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Mar. 31, 2014 Other Debt Obligations [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Dec. 31, 2013 Other Debt Obligations [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Mar. 31, 2014 Other Debt Obligations [Member] Fair Value, Inputs, Level 2 [Member] USD ($)	Dec. 31, 2013 Other Debt Obligations [Member] Fair Value, Inputs, Level 2 [Member] USD ($)	Mar. 31, 2014 Other Debt Obligations [Member] Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2013 Other Debt Obligations [Member] Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Mar. 31, 2014 Collateralized Mortgage Backed Securities [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2013 Collateralized Mortgage Backed Securities [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Mar. 31, 2014 Collateralized Mortgage Backed Securities [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Dec. 31, 2013 Collateralized Mortgage Backed Securities [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Mar. 31, 2014 Collateralized Mortgage Backed Securities [Member] Fair Value, Inputs, Level 2 [Member] USD ($)	Dec. 31, 2013 Collateralized Mortgage Backed Securities [Member] Fair Value, Inputs, Level 2 [Member] USD ($)	Mar. 31, 2014 Collateralized Mortgage Backed Securities [Member] Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2013 Collateralized Mortgage Backed Securities [Member] Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Mar. 31, 2014 Asset-backed Securities [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2013 Asset-backed Securities [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Mar. 31, 2014 Asset-backed Securities [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Dec. 31, 2013 Asset-backed Securities [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Mar. 31, 2014 Asset-backed Securities [Member] Fair Value, Inputs, Level 2 [Member] USD ($)	Dec. 31, 2013 Asset-backed Securities [Member] Fair Value, Inputs, Level 2 [Member] USD ($)	Mar. 31, 2014 Asset-backed Securities [Member] Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2013 Asset-backed Securities [Member] Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Mar. 31, 2014 Equity Securities, US [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2013 Equity Securities, US [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Mar. 31, 2014 Equity Securities, US [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Dec. 31, 2013 Equity Securities, US [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Mar. 31, 2014 Equity Securities, US [Member] Fair Value, Inputs, Level 1 [Member] USD ($)	Dec. 31, 2013 Equity Securities, US [Member] Fair Value, Inputs, Level 1 [Member] USD ($)	Mar. 31, 2014 Equity Securities, US [Member] Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2013 Equity Securities, US [Member] Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Mar. 31, 2014 Equity Method and Other Investments [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2013 Equity Method and Other Investments [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Mar. 31, 2014 Equity Method and Other Investments [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Dec. 31, 2013 Equity Method and Other Investments [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Mar. 31, 2014 Buy British pound Sell euro [Member] EUR (€)	Mar. 31, 2014 Buy British pound Sell euro [Member] GBP (£)	Mar. 31, 2014 Buy US dollar Sell euro [Member] USD ($)	Mar. 31, 2014 Buy US dollar Sell euro [Member] EUR (€)	Mar. 31, 2014 Buy euro Sell US dollar [Member] USD ($)	Mar. 31, 2014 Buy euro Sell US dollar [Member] EUR (€)	Mar. 31, 2014 Buy US dollar Sell Japanese Yen [Member] USD ($)	Mar. 31, 2014 Buy US dollar Sell Japanese Yen [Member] JPY (¥)
Repayments of Long-term Debt	$ 1,002.0	$ 0.9
Available-for-sale Securities, Debt Securities	7,829.7
Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge										51.8	(69.0)
Cash and Cash Equivalents, Fair Value Disclosure														3,888.0	3,830.2							3,888.0	3,830.2	3,668.2	3,772.6	219.8	57.6							3,888.0	3,830.2
Long-term Debt					(600.0)		(400.0)							(5,264.4)	(5,212.9)											(5,595.5)	(5,490.9)							(5,595.5)	(5,490.9)
Debt Instrument, Interest Rate, Stated Percentage				1.95%		4.65%
Derivative Assets, Current																			20.1	6.4	6.7										20.1	6.4	6.7						20.1	6.4	6.7
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Other, Percentage of Nonperforming Assets	85.00%
Maximum Remaining Maturity of Foreign Currency Derivatives	30 days
Description of Derivative Activity Volume Percent	50.00%
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments												(51.8)	69.0
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	9.0
Derivative Instruments, Loss Reclassified from Accumulated OCI into Income, Effective Portion								39.5	0			2.2	2.2
Derivative Instruments, Gain (Loss) Recognized in Income, Net	(0.3)	0.1
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net								85.9	1.1
Derivative Assets, Noncurrent																		334.1	278.7											334.1	278.7							334.1	278.7
Derivative Liabilities, Current																(63.7)	(149.6)			(8.0)	(7.1)							(63.7)	(149.6)			(8.0)	(7.1)			(63.7)	(149.6)			(8.0)	(7.1)
Derivative Liabilities, Noncurrent																		(1.2)	(0.9)											(1.2)	(0.9)							(1.2)	(0.9)
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value	5,304.3
Available-for-sale Securities, Gross Unrealized Gains	293.9		375.6
Available-for-sale Securities, Gross Unrealized Losses	38.3		59.8
Available-for-sale Securities, Continuous Unrealized Gain Position, Fair Value	5,356.0		4,982.7
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	2,607.6		3,664.7
Other than Temporary Impairment Losses, Investments	0	5.2
Proceeds from Sale and Maturity of Available-for-sale Securities	3,742.2	3,705.9
Available-for-sale Securities, Gross Realized Gains	79.8	10.0						69.0
Available-for-sale Securities, Gross Realized Losses	4.0	2.5
Available-for-sale Securities, Current [Abstract]
Available-for-sale Securities, Debt Securities, Current																																										841.8	931.7	838.9	929.8	841.8	931.7	841.8	931.7	151.1	276.4	151.0	276.6	151.1	276.4			151.1	276.4	106.8	106.8	106.8	106.8	2.5	2.7	2.5	2.7	2.5	2.7	2.5	2.7
Available-for-sale Securities, Equity Securities, Current																																																																																								222.2	356.3	56.3	75.0	222.2	356.3	222.2	356.3
Available-for-sale Securities, Current, Total														1,324.4	1,567.1							1,155.5	1,284.1
Available-for-sale Securities, Noncurrent [Abstract]
Available-for-sale Securities, Debt Securities, Noncurrent																																										4,569.5	4,940.5	4,545.5	4,933.7	4,569.5	4,940.5	4,569.5	4,940.5	854.0	1,115.6	860.3	1,126.1	843.2	1,035.6	10.8	80.0	854.0	1,115.6	122.7	122.7	122.7	122.7	7.6	7.3	8.2	8.3	7.6	7.3	7.6	7.3	631.9	636.0	644.0	652.4	631.9	636.0	631.9	636.0	541.8	490.0	546.0	494.5	541.8	490.0	541.8	490.0
Available-for-sale Securities, Equity Securities, Noncurrent																																																																																								108.7	81.2	22.8	22.8	108.7	81.2	108.7	81.2
Other Long-term Investments																																																																																																368.6	354.3	368.6	354.3
Available-for-sale Securities, Noncurrent, Total														7,204.8	7,624.9							7,118.1	7,592.1
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value	1,102.2
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value	662.2
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value	761.0
Derivative Liability, Notional Amount																																																																																																					100.6	290.4			422.7	269.2
Derivative Asset, Notional Amount																																																																																																				€ 120.2			€ 209.9	$ 585.8			¥ 27,470.0