Debt and Credit Facilities (Long-Term Debt Excluding Current Maturities) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Long-term debt excluding current maturities	$ 2,271.1	$ 2,269.3
9.500% Senior Notes Due 2014 [Member]
Long-term debt excluding current maturities	655.0	655.0
5.50% Senior Notes Due 2015 [Member]
Long-term debt excluding current maturities	198.4	196.4
4.75% Senior Notes Due 2015 [Member]
Long-term debt excluding current maturities	299.7	299.7
6.875% Senior Notes Due 2018 [Member]
Long-term debt excluding current maturities	749.4	749.4
9.00% Debentures Due 2021 [Member]
Long-term debt excluding current maturities	125.0	125.0
7.20% Debentures Due 2014-2025 [Member]
Long-term debt excluding current maturities	90.0	90.0
6.48% Debentures Due 2025 [Member]
Long-term debt excluding current maturities	149.7	149.7
Other Loans and Notes [Member]
Long-term debt excluding current maturities	$ 3.9	$ 4.1