Guarantor and Non-Guarantor Supplemental Financial Information - Schedule of Balance Sheet Information (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
ASSETS
Total current assets	$ 7,735	$ 5,197
Investment in subsidiaries	0	0
Intangible assets, net	1,804	1,992
Goodwill	8,127	8,120	$ 8,229
Other assets, net	3,750	2,724
TOTAL ASSETS	21,416	18,033
LIABILITIES AND STOCKHOLDERS’ EQUITY
Total current liabilities	10,714	8,060
Long-term debt, excluding current maturities	4,189	3,717
Other long-term liabilities	962	575
Redeemable non-controlling interests	15	30	22	$ 0
Stockholders’ equity	5,536	5,651	$ 6,129	$ 5,693
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	21,416	18,033
Reportable Legal Entities | Parent
ASSETS
Total current assets	443	402
Investment in subsidiaries	11,345	10,615
Intangible assets, net	0	0
Goodwill	0	0
Other assets, net	0	0
TOTAL ASSETS	11,788	11,017
LIABILITIES AND STOCKHOLDERS’ EQUITY
Total current liabilities	2,063	1,649
Long-term debt, excluding current maturities	4,189	3,717
Other long-term liabilities	0	0
Redeemable non-controlling interests	0	0
Stockholders’ equity	5,536	5,651
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	11,788	11,017
Reportable Legal Entities | Guarantor Subsidiaries
ASSETS
Total current assets	7,416	5,261
Investment in subsidiaries	3,297	3,425
Intangible assets, net	1,414	1,520
Goodwill	6,366	6,366
Other assets, net	2,540	1,840
TOTAL ASSETS	21,033	18,412
LIABILITIES AND STOCKHOLDERS’ EQUITY
Total current liabilities	9,097	7,396
Long-term debt, excluding current maturities	0	0
Other long-term liabilities	506	320
Redeemable non-controlling interests	15	17
Stockholders’ equity	11,415	10,679
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	21,033	18,412
Reportable Legal Entities | Non-Guarantor Subsidiaries
ASSETS
Total current assets	2,588	2,137
Investment in subsidiaries	0	0
Intangible assets, net	390	472
Goodwill	1,761	1,754
Other assets, net	1,248	913
TOTAL ASSETS	5,987	5,276
LIABILITIES AND STOCKHOLDERS’ EQUITY
Total current liabilities	2,266	1,618
Long-term debt, excluding current maturities	0	0
Other long-term liabilities	494	284
Redeemable non-controlling interests	0	13
Stockholders’ equity	3,227	3,361
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	5,987	5,276
Eliminations
ASSETS
Total current assets	(2,712)	(2,603)
Investment in subsidiaries	(14,642)	(14,040)
Intangible assets, net	0	0
Goodwill	0	0
Other assets, net	(38)	(29)
TOTAL ASSETS	(17,392)	(16,672)
LIABILITIES AND STOCKHOLDERS’ EQUITY
Total current liabilities	(2,712)	(2,603)
Long-term debt, excluding current maturities	0	0
Other long-term liabilities	(38)	(29)
Redeemable non-controlling interests	0	0
Stockholders’ equity	(14,642)	(14,040)
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ (17,392)	$ (16,672)