Other Comprehensive Income (Loss) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Dec. 31, 2012
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Prior Service Cost Arising During Period, before Tax	$ (6.4)	$ (4.3)
Accumulated other comprehensive loss	(1,957.3)	(4,014.4)	(2,002.7)	(3,797.1)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	23.6	(291.6)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment Realized upon Sale or Liquidation, Net of Tax	21.8	74.3
Other comprehensive income (loss), net of tax	45.4	(217.3)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, before Tax	74.2	119.0
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized in Net Periodic Benefit Cost, before Tax	67.8	114.7
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net (Gain) Loss, Tax	(23.7)	(38.6)
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net (Gain) Loss, Net of Tax	44.1	76.1
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax	21.2	(10.1)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, before Reclassification Adjustments, Tax	23.5	47.2
Other Comprehensive Income, Other, Net of Tax	(22.3)	(1.8)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	22.4	0.7
Accumulated Translation Adjustment [Member]
Accumulated other comprehensive loss	459.7	80.8	463.0	426.8
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	(3.3)	(346.0)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment Realized upon Sale or Liquidation, Net of Tax	0	0
Other comprehensive income (loss), net of tax	(3.3)	(346.0)
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated other comprehensive loss	166.2	90.5	205.2	72.5
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	10.3	21.3
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment Realized upon Sale or Liquidation, Net of Tax	(49.3)	(3.3)
Other comprehensive income (loss), net of tax	(39.0)	18.0
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated other comprehensive loss	(2,443.5)	(4,086.7)	(2,489.1)	(4,195.2)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	1.5	32.4
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment Realized upon Sale or Liquidation, Net of Tax	44.1	76.1
Other comprehensive income (loss), net of tax	45.6	108.5
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated other comprehensive loss	(139.7)	(99.0)	(181.8)	(101.2)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	15.1	0.7
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment Realized upon Sale or Liquidation, Net of Tax	27.0	1.5
Other comprehensive income (loss), net of tax	$ 42.1	$ 2.2