Equity Equity (Changes in Accumulated Other Comprehensive Income (Loss)) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2013
Balance at December 31:	$ (521.0)
Other comprehensive income before reclassifications	5.6
Amounts reclassified from accumulated other comprehensive income	59.4
Tax (expense) benefit	(17.0)
Balance at June 30:	(473.0)
Cash flow hedges and marketable securities [Member]
Balance at December 31:	(1.4)
Other comprehensive income before reclassifications	9.4
Amounts reclassified from accumulated other comprehensive income	9.6
Tax (expense) benefit	(0.3)
Balance at June 30:	17.3
Pension and OPEB Adjustments [Member]
Balance at December 31:	(964.2)
Other comprehensive income before reclassifications	(1.1)
Amounts reclassified from accumulated other comprehensive income	49.8
Tax (expense) benefit	(16.7)
Balance at June 30:	(932.2)
Foreign Currency Gain (Loss) [Member]
Balance at December 31:	444.6
Other comprehensive income before reclassifications	(2.7)
Amounts reclassified from accumulated other comprehensive income	0
Tax (expense) benefit	0
Balance at June 30:	$ 441.9