Interim Condensed Consolidated Financial Statements - Schedule of Revenues from Third Party Payers and Uninsured (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenues [Line Items]
Revenues from third party payers	$ 8,351	$ 8,102	$ 25,310	$ 24,837
Uninsured	717	576	1,809	1,757
Other	343	215	959	651
Revenues before provision for doubtful accounts	9,411	8,893	28,078	27,245
Provision for doubtful accounts	(955)	(831)	(2,732)	(2,666)
Revenues	8,456	8,062	25,346	24,579
Revenues from third party payers, ratio	98.70%	100.40%	99.80%	101.00%
Uninsured Ratio	8.50%	7.10%	7.10%	7.10%
Other Ratio	4.10%	2.70%	3.80%	2.70%
Revenues before provision for doubtful accounts, ratio	111.30%	110.20%	110.70%	110.80%
Provision for doubtful accounts Ratio	(11.30%)	(10.20%)	(10.70%)	(10.80%)
Revenues ratio from third party payers	100.00%	100.00%	100.00%	100.00%
Medicare [Member]
Revenues [Line Items]
Revenues from third party payers	1,847	1,949	5,961	6,251
Revenues from third party payers, ratio	21.80%	24.20%	23.50%	25.40%
Managed Medicare [Member]
Revenues [Line Items]
Revenues from third party payers	794	720	2,441	2,199
Revenues from third party payers, ratio	9.40%	8.90%	9.60%	8.90%
Medicaid [Member]
Revenues [Line Items]
Revenues from third party payers	401	378	1,098	1,188
Revenues from third party payers, ratio	4.70%	4.70%	4.30%	4.80%
Managed Medicaid [Member]
Revenues [Line Items]
Revenues from third party payers	386	380	1,165	1,080
Revenues from third party payers, ratio	4.60%	4.70%	4.60%	4.40%
Managed Care and Other Insurers [Member]
Revenues [Line Items]
Revenues from third party payers	4,636	4,422	13,777	13,340
Revenues from third party payers, ratio	54.80%	54.80%	54.40%	54.30%
International (Managed Care and Other Insurers) [Member]
Revenues [Line Items]
Revenues from third party payers	$ 287	$ 253	$ 868	$ 779
Revenues from third party payers, ratio	3.40%	3.10%	3.40%	3.20%