Long-term Debt (Details) (USD $) In Millions, unless otherwise specified					12 Months Ended			1 Months Ended	12 Months Ended			12 Months Ended				12 Months Ended				12 Months Ended				12 Months Ended			12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2013 6.25% Senior Unsecured Notes due 2014		Dec. 31, 2012 6.25% Senior Unsecured Notes due 2014	Jul. 31, 2013 10.00% Senior Unsecured Notes due 2017	Dec. 31, 2013 10.00% Senior Unsecured Notes due 2017		Dec. 31, 2012 10.00% Senior Unsecured Notes due 2017	Dec. 31, 2013 2.25% Senior Notes due 2017		Dec. 31, 2012 2.25% Senior Notes due 2017	Nov. 08, 2012 2.25% Senior Notes due 2017	Dec. 31, 2013 4.00% Senior Notes due 2022		Dec. 31, 2012 4.00% Senior Notes due 2022	Mar. 02, 2012 4.00% Senior Notes due 2022	Dec. 31, 2013 3.75% Senior Notes due 2023		Dec. 31, 2012 3.75% Senior Notes due 2023	Nov. 08, 2012 3.75% Senior Notes due 2023	Dec. 31, 2013 4.75% Convertible Senior Notes due 2023		Dec. 31, 2012 4.75% Convertible Senior Notes due 2023	Dec. 31, 2013 4.25% Convertible Senior Notes due 2023	Dec. 31, 2013 Other notes payable and capitalized leases		Dec. 31, 2012 Other notes payable and capitalized leases
Debt Instrument
Write off of Unamortized Discount									$ 7.3
Effective Interest Rate					6.29%				2.30%			4.13%				4.32%
Stated Interest Rate					6.25%				10.00%			2.25%				4.00%				3.75%				4.75%			4.25%
Book Value					351.3		352.8		299.4		299.3	247.4		247.1		498.6		498.5		0		591.9		0		200.5		86.7		87.3
Fair Value					365.6	[1]	372.6		293.0	[1]	297.8	241.6	[1]	258.7		467.3	[1]	499.7		0	[1]	660.8		0	[1]	202.8		87.8	[1]	90.8
Total long-term debt	1,483.4		2,277.4
Less: current portion	353.6	[2]	216.6	[2]
Long-term debt, excluding current portion	1,129.8		2,060.8
Face Value															300.0				250.0				500.0
Debt Maturity Date					Nov. 15, 2014				Jul. 15, 2017			Nov. 15, 2017				Mar. 15, 2022				Feb. 15, 2023				Mar. 15, 2023			Mar. 15, 2023
Redemption of Convertible Notes for cash, date								Jul. 15, 2013
Unamortized Discount															$ 0.7				$ 3.2				$ 1.5

[1] See Note 12 for information on the fair value measurement of our long-term debt.

[2] We included our 6.25% Senior Unsecured Notes due 2014 (the "6.25% Notes") in the current portion of long-debt on our December 31, 2013 Consolidated Balance Sheet because the 6.25% Notes are scheduled to mature on November 15, 2014. We included our 4.75% Convertible Senior Notes due 2023 (the "4.75% Notes") in the current portion of long-term debt on our December 31, 2012 Consolidated Balance Sheet because holders of the 4.75% Notes had an option to require us to repurchase their Notes for cash, stock, or a combination, at our election, at par on March 15, 2013. The 4.75% Notes were retired in the first quarter of 2013.