Earnings Per Common Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Earnings Per Common Share
Net income (loss)	$ 324.1	$ 190.0
Subtract:
Net income (loss) attributable to noncontrolling interest	22.2	3.5
Preferred stock dividends	8.2	8.2
Adjustments to redemption amounts of redeemable noncontrolling interests	9.7
Total	$ 284.0	$ 178.3
Weighted-average shares outstanding
Basic	295.8	294.1
Dilutive effects:
Stock options	1.6	1.1
Restricted stock units	1.8	1.7
Performance share awards	0.3	0.2
Diluted	299.5	297.1
Net income (loss) per common share:
Basic	$ 0.96	$ 0.61
Diluted	$ 0.95	$ 0.61