Debt and Credit Facilities (Long-Term Debt Excluding Current Maturities) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Long-term debt excluding current maturities	$ 3,152.3	$ 3,153.5
5.50% Senior Notes Due 2015 [Member]
Long-term debt excluding current maturities	198.5	198.1
4.75% Senior Notes Due 2015 [Member]
Long-term debt excluding current maturities	299.8	299.8
6.875% Senior Notes Due 2018 [Member]
Long-term debt excluding current maturities	749.5	749.5
2.875% Senior notes due 2019 [Member]
Long-term debt excluding current maturities	349.5	349.5
9.00% Debentures Due 2021 [Member]
Long-term debt excluding current maturities	125.0	125.0
4.25% Senior notes due 2023 [Member]
Long-term debt excluding current maturities	698.8	698.8
7.20% Debentures Due 2014-2025 [Member]
Long-term debt excluding current maturities	82.5	82.5
6.48% Debentures Due 2025 [Member]
Long-term debt excluding current maturities	149.7	149.7
5.75% Senior notes due 2043 [Member]
Long-term debt excluding current maturities	498.0	498.0
Other Loans and Notes [Member]
Long-term debt excluding current maturities	$ 1.0	$ 2.6