Accumulated Other Comprehensive Income (Loss) Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI, beginning balance	$ 11,037	$ 10,836	$ 10,613	$ 11,022	$ 10,836	$ 11,022
Other Comprehensive Income (Loss), before Tax [Abstract]
Net change, Net of Tax Amount			38		(11)	(97)
Other comprehensive income (loss)	1		76		(28)	(150)
Other Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Total stockholders’ equity	11,205	11,037	10,972	10,613	11,205	10,972
Foreign currency translation adjustments: [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI before tax, beginning balance	29	56	(202)	(63)	56	(63)
AOCI tax, beginning balance	1	(1)	3	(1)	(1)	(1)
AOCI, beginning balance	30	55	(199)	(64)	55	(64)
Other Comprehensive Income (Loss), before Tax [Abstract]
Net change, Before Tax Amount	15		37		(12)	(102)
Net change, Tax Effect	(1)		1		1	5
Other comprehensive income (loss)	14		38			(97)
Other Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
AOCI before tax, ending balance	44	29	(165)	(202)	44	(165)
AOCI tax, ending balance	0	1	4	3	0	4
Total stockholders’ equity	44	30	(161)	(199)	44	(161)
Unrealized gains on cash flow hedges: [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI before tax, beginning balance	63	67	(79)	31	67	31
AOCI tax, beginning balance	(12)	(12)	14	(5)	(12)	(5)
AOCI, beginning balance	51	55	(65)	26	55	26
Other Comprehensive Income (Loss), before Tax [Abstract]
Net change, Before Tax Amount	(17)		46		(21)	(64)
Net change, Tax Effect	4		(8)		4	11
Other comprehensive income (loss)	(13)		38		(17)	(53)
Other Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
OCI, before reclassifications, before tax	(3)		35		14	(78)
Other comprehensive income (loss) before reclassifications, tax	0		(6)		(3)	13
OCI, before reclassifications, net of tax	(3)		29		11	(65)
AOCI before tax, ending balance	46	63	(33)	(79)	46	(33)
AOCI tax, ending balance	(8)	(12)	6	14	(8)	6
Total stockholders’ equity	38	51	(27)	(65)	38	(27)
Unrealized gains on cash flow hedges: [Member] | Cost of revenues [Member]
Other Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Reclassification from AOCI, current period, before tax	(12)		9		(30)	12
Reclassification from AOCI, current period, tax	3		(2)		6	(2)
Reclassification from AOCI, current period, net of tax	(9)		7		(24)	10
Unrealized gains on cash flow hedges: [Member] | Selling, general and administrative expenses [Member]
Other Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Reclassification from AOCI, current period, before tax	(2)		2		(5)	2
Reclassification from AOCI, current period, tax	1		0		1	0
Reclassification from AOCI, current period, net of tax	(1)		2		(4)	2
Accumulated other comprehensive income (loss):
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI before tax, beginning balance	92	123	(281)	(32)	123	(32)
AOCI tax, beginning balance	(11)	(13)	17	(6)	(13)	(6)
AOCI, beginning balance	81	110	(264)	(38)	110	(38)
Other Comprehensive Income (Loss), before Tax [Abstract]
Net change, Before Tax Amount	(2)		83		(33)	(166)
Net change, Tax Effect	3		(7)		5	16
Other comprehensive income (loss)	1	(29)	76	(226)	(28)	(150)
Other Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
AOCI before tax, ending balance	90	92	(198)	(281)	90	(198)
AOCI tax, ending balance	(8)	(11)	10	17	(8)	10
Total stockholders’ equity	$ 82	$ 81	$ (188)	$ (264)	$ 82	$ (188)