Debt and Credit Facilities (Long-Term Debt Excluding Current Maturities) (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Long-term debt excluding current maturities	$ 3,734.6	$ 3,741.7
6.875% Senior Notes Due 2018 [Member]
Long-term debt excluding current maturities	749.7	749.6
2.875% Senior notes due 2019 [Member]
Long-term debt excluding current maturities	349.6	349.6
Two Point Six Two Five Percent Senior Notes Due Two Thousand Twenty [Member]
Long-term debt excluding current maturities	299.8	299.8
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	698.9	698.9
7.20% Debentures Due 2014-2025 [Member]
Long-term debt excluding current maturities	67.5	75.0
Three Point Five Five Percent Senior Notes due 2024 [Member]
Long-term debt excluding current maturities	497.3	497.2
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
Four Point Six Five Percent Senior Notes due Twenty Forty Four [Member]
Long-term debt excluding current maturities	298.2	298.2
Other Loans and Notes [Member]
Long-term debt excluding current maturities	$ 0.9	$ 0.7