Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income	$ 2,743	$ 3,432	$ 2,696
Increase (decrease) in cash from operating assets and liabilities:
Accounts receivable	(4,640)	(3,247)	(4,114)
Provision for doubtful accounts	4,039	3,257	3,913
Accounts receivable, net	(601)	10	(201)
Inventories and other assets	(69)	(112)	(314)
Accounts payable and accrued expenses	374	144	192
Depreciation and amortization	2,131	1,966	1,904
Income taxes	433	123	(160)
Losses (gains) on sales of facilities	(8)	(23)	5
Losses on retirement of debt	39	4	135
Legal claim costs (benefits)		(246)	249
Amortization of debt issuance costs	31	34	35
Share-based compensation	270	251	239
Other	83	70	54
Net cash provided by (used in) operating activities	5,426	5,653	4,734
Cash flows from investing activities:
Purchase of property and equipment	(3,015)	(2,760)	(2,375)
Acquisition of hospitals and health care entities	(1,212)	(576)	(351)
Disposal of hospitals and health care entities	25	26	73
Change in investments	(73)	64	63
Other	(4)	6	7
Net cash used in investing activities	(4,279)	(3,240)	(2,583)
Cash flows from financing activities:
Issuances of long-term debt	1,502	5,400	5,548
Net change in revolving bank credit facilities	760	(110)	150
Repayment of long-term debt	(753)	(4,475)	(4,920)
Distributions to noncontrolling interests	(448)	(434)	(495)
Payment of debt issuance costs	(26)	(40)	(50)
Repurchases of common stock	(2,051)	(2,751)	(2,397)
Other	(45)	(98)	188
Net cash (used in) provided by financing activities	(1,061)	(2,508)	(1,976)
Change in cash and cash equivalents	86	(95)	175
Cash and cash equivalents at beginning of period	646	741	566
Cash and cash equivalents at end of period	732	646	741
Interest payments	1,700	1,666	1,650
Income tax payments, net	$ 1,205	$ 1,255	$ 1,186