Debt (Summary of Long-Term Debt) (Details) (USD $) In Millions, unless otherwise specified								3 Months Ended						3 Months Ended						3 Months Ended						3 Months Ended						3 Months Ended						3 Months Ended						3 Months Ended						3 Months Ended						3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014 Revolving Facility	Dec. 31, 2013 Revolving Facility	Mar. 31, 2014 Convertible Debt Cash Convertible Notes	Dec. 31, 2013 Convertible Debt Cash Convertible Notes	Sep. 15, 2008 Convertible Debt Cash Convertible Notes	Mar. 31, 2014 Senior Notes 2016 Senior Notes (1.800% coupon)		Dec. 31, 2013 Senior Notes 2016 Senior Notes (1.800% coupon)		Jun. 18, 2013 Senior Notes 2016 Senior Notes (1.800% coupon)		Mar. 31, 2014 Senior Notes 2016 Senior Notes (1.350% coupon)		Dec. 31, 2013 Senior Notes 2016 Senior Notes (1.350% coupon)		Nov. 13, 2013 Senior Notes 2016 Senior Notes (1.350% coupon)		Mar. 31, 2014 Senior Notes 2018 Senior Notes (2.600% coupon)		Dec. 31, 2013 Senior Notes 2018 Senior Notes (2.600% coupon)		Jun. 18, 2013 Senior Notes 2018 Senior Notes (2.600% coupon)		Mar. 31, 2014 Senior Notes 2018 Senior Notes (6.000% coupon)		Dec. 31, 2013 Senior Notes 2018 Senior Notes (6.000% coupon)		Nov. 09, 2010 Senior Notes 2018 Senior Notes (6.000% coupon)		Mar. 31, 2014 Senior Notes 2019 Senior Notes (2.550% coupon)		Dec. 31, 2013 Senior Notes 2019 Senior Notes (2.550% coupon)		Nov. 13, 2013 Senior Notes 2019 Senior Notes (2.550% coupon)		Mar. 31, 2014 Senior Notes 2020 Senior Notes (7.875% coupon)		Dec. 31, 2013 Senior Notes 2020 Senior Notes (7.875% coupon)		May 12, 2010 Senior Notes 2020 Senior Notes (7.875% coupon)		Mar. 31, 2014 Senior Notes 2023 Senior Notes (3.125% coupon)		Dec. 31, 2013 Senior Notes 2023 Senior Notes (3.125% coupon)		Dec. 12, 2012 Senior Notes 2023 Senior Notes (3.125% coupon)		Mar. 31, 2014 Senior Notes 2023 Senior Notes (4.200% coupon)		Dec. 31, 2013 Senior Notes 2023 Senior Notes (4.200% coupon)		Nov. 13, 2013 Senior Notes 2023 Senior Notes (4.200% coupon)		Mar. 31, 2014 Senior Notes 2043 Senior Notes (5.400% coupon)		Dec. 31, 2013 Senior Notes 2043 Senior Notes (5.400% coupon)		Jun. 18, 2013 Senior Notes 2043 Senior Notes (5.400% coupon)		Mar. 31, 2014 Senior Notes Other	Dec. 31, 2013 Senior Notes Other
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage							3.75%					1.80%	[1]					1.35%	[2]					2.60%	[3]					6.00%	[4]					2.55%	[1]					7.875%	[4]					3.125%	[1]					4.20%	[5]					5.40%	[5]
Net debt carrying amount			$ 0	$ 60.0	$ 2,066.8	$ 1,828.3		$ 499.3	[1]	$ 499.2	[1]			$ 499.7	[2]	$ 499.7	[2]			$ 648.8	[3]	$ 648.8	[3]			$ 810.7	[4]	$ 811.4	[4]			$ 498.8	[1]	$ 498.8	[1]			$ 1,011.7	[4]	$ 1,012.0	[4]			$ 749.7	[1]	$ 733.2	[1]			$ 498.1	[5]	$ 498.1	[5]			$ 496.9	[5]	$ 496.9	[5]			$ 0.1	$ 0.1
Long-term debt, excluding current maturities	$ 7,780.6	$ 7,586.5
Equivalent percentage of redeemed amount								100.00%						100.00%						100.00%						100.00%						100.00%						100.00%						100.00%						100.00%						100.00%
Debt instrument, basis spread on variable rate								0.20%						0.125%						0.30%						0.50%						0.20%						0.50%						0.20%						0.25%						0.25%

[1] (a)Instrument is callable by the Company at any time at the greater of 100% of the principal amount or the sum of the present values of the remaining scheduled payments of principal and interest discounted at the U.S. Treasury rate plus 0.20% plus, in each case, accrued and unpaid interest.

[2] (b)Instrument is callable by the Company at any time at the greater of 100% of the principal amount or the sum of the present values of the remaining scheduled payments of principal and interest discounted at the U.S. Treasury rate plus 0.125% plus, in each case, accrued and unpaid interest.

[3] Instrument is callable by the Company at any time at the greater of 100% of the principal amount or the sum of the present values of the remaining scheduled payments of principal and interest discounted at the U.S. Treasury rate plus 0.50% plus, in each case, accrued and unpaid interest.

[4] (c) Instrument is callable by the Company at any time at the greater of 100% of the principal amount or the sum of the present values of the remaining scheduled payments of principal and interest discounted at the U.S. Treasury rate plus 0.30% plus, in each case, accrued and unpaid interest.

[5] (e) Instrument is callable by the Company at any time at the greater of 100% of the principal amount or the sum of the present values of the remaining scheduled payments of principal and interest discounted at the U.S. Treasury rate plus 0.25% plus, in each case, accrued and unpaid interest.