Accumulated Other Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated other comprehensive loss	$ (1,230)	$ (1,260)	$ (1,666)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	(17)	36
Other Comprehensive Income (Loss), Before Reclassifications, Tax	33	269
Change in other comprehensive income, Separation and Merger Transaction		37
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	14	64
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	30	406
Foreign Currency Translation Adjustment, Tax	40
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated other comprehensive loss	(22)	(38)	6
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	(17)	36
Other Comprehensive Income (Loss), Before Reclassifications, Tax	33	(80)
Change in other comprehensive income, Separation and Merger Transaction		0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	16	(44)
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated other comprehensive loss	(1,146)	(1,157)	(1,597)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	0	0
Other Comprehensive Income (Loss), Before Reclassifications, Tax	(4)	330
Change in other comprehensive income, Separation and Merger Transaction		33
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	15	77
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	11	440
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated other comprehensive loss	(62)	(65)	(75)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	0	0
Other Comprehensive Income (Loss), Before Reclassifications, Tax	4	19
Change in other comprehensive income, Separation and Merger Transaction		4
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(1)	(13)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	$ 3	$ 10