Shareholders' Equity (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Accumulated other comprehensive income (loss)
Balance of Accumulated Other Comprehensive Income (Loss) at End of period	$ (1,241)	$ (57)
Foreign Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(953)	131
Accumulated other comprehensive income (loss)
Balance of Accumulated Other Comprehensive Income (Loss) at beginning of period	269	136
Net realized gains (losses)	0	0
Other Comprehensive Income (Loss), Tax	30	2
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(923)	133
Balance of Accumulated Other Comprehensive Income (Loss) at End of period	(654)	269
Deferred Gain (Loss) On Hedging Activities [Member]
Accumulated Other Comprehensive Income [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(119)	(35)
Accumulated other comprehensive income (loss)
Balance of Accumulated Other Comprehensive Income (Loss) at beginning of period	5	4
Net realized gains (losses)	187	37
Other Comprehensive Income (Loss), Tax	(26)	(1)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	42	1
Balance of Accumulated Other Comprehensive Income (Loss) at End of period	47	5
Pension Liability Adjustment [Member]
Accumulated Other Comprehensive Income [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(485)	354
Accumulated other comprehensive income (loss)
Balance of Accumulated Other Comprehensive Income (Loss) at beginning of period	(330)	(590)
Net realized gains (losses)	21	60
Other Comprehensive Income (Loss), Tax	164	(154)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(300)	260
Balance of Accumulated Other Comprehensive Income (Loss) at End of period	(630)	(330)
Unrealized Gain (Loss) On Investments [Member]
Accumulated Other Comprehensive Income [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(11)	(157)
Accumulated other comprehensive income (loss)
Balance of Accumulated Other Comprehensive Income (Loss) at beginning of period	(1)	0
Net realized gains (losses)	6	157
Other Comprehensive Income (Loss), Tax	2	(1)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(3)	(1)
Balance of Accumulated Other Comprehensive Income (Loss) at End of period	(4)	(1)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(1,568)	293
Accumulated other comprehensive income (loss)
Balance of Accumulated Other Comprehensive Income (Loss) at beginning of period	(57)	(450)
Net realized gains (losses)	214	254
Other Comprehensive Income (Loss), Tax	170	(154)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(1,184)	393
Balance of Accumulated Other Comprehensive Income (Loss) at End of period	$ (1,241)	$ (57)