Accumulated Other Comprehensive Loss (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014 Accumulated Translation Adjustment [Member]	Jun. 30, 2013 Accumulated Translation Adjustment [Member]	Jun. 30, 2014 Accumulated Net Gain Loss From Designated Or Qualifying Cash Flow Hedges [Member]	Jun. 30, 2013 Accumulated Net Gain Loss From Designated Or Qualifying Cash Flow Hedges [Member]	Jun. 30, 2014 Accumulated Defined Benefit Plans Adjustment [Member]	Jun. 30, 2013 Accumulated Defined Benefit Plans Adjustment [Member]	Jun. 30, 2013 Accumulated Net Unrealized Investment Gain Loss [Member]	Jun. 30, 2014 Accumulated Net Unrealized Investment Gain Loss [Member]	Dec. 31, 2013 Accumulated Net Unrealized Investment Gain Loss [Member]
Accumulated other comprehensive loss
Balance at the beginning of the period			$ (583.0)	$ (475.0)	$ (489.0)	$ (335.0)	$ (40.0)	$ (17.0)	$ (53.0)	$ (121.0)	$ (2.0)	$ (1.0)	$ (1.0)
Gains (losses) on cash-flow hedges, net of income tax effect of $1 and ($11) for the six months ended June 30, 2014 and 2013, respectively	(25)	(16)	1	(26)			1	(26)
Amount of (gains) losses on cash flow hedges reclassified to earnings, net of income tax effect of ($6), and $5 for the six months ended June 30, 2014 and 2013, respectively		3	13	(8)			13	(8)
Losses related to pension and other postretirement obligations reclassified to earnings, net of income tax effect	1	2	2	3					2	3
Unrealized gain on investment, net of income tax effect		1		1							1
Currency translation adjustment	37	(88)	5	(110)	5	(110)
Balance at end of the period	(562.0)	(615.0)	(562.0)	(615.0)	(484.0)	(445.0)	(26.0)	(51.0)	(51.0)	(118.0)	(1.0)	(1.0)	(1.0)
Income tax effect of accumulated other comprehensive gain (loss)
Gains (losses) on cash flow hedges, income tax effect	(12)	(8)	1	(11)			1	(11)
Amount of (gains) losses on cash flow hedges reclassified to earnings, income tax effect		$ (2)	$ (6)	$ 5			$ (6)	$ 5