SCHEDULE I - PARENT COMPANY FINANCIAL INFORMATION (Condensed Statements of Cash Flows) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Condensed Financial Statements, Captions [Line Items]
Net cash provided by operating activities	$ 2,966	$ 3,981	$ 4,587
Cash flows from investing activities:
Acquisitions, net of cash acquired	(89)	(233)	(337)
Purchases of property and equipment, net	(575)	(1,004)	(1,137)
Purchases of investment securities	(8,185)	(7,552)	(6,049)
Proceeds from sale of investment securities	3,376	3,795	2,434
Maturities of investment securities	2,982	1,292	1,365
Other	(50)	0	0
Net cash used in investing activities	(2,952)	(3,492)	(1,006)
Cash flows from financing activities:
Proceeds from issuance of senior notes, net	2,232	2,544	1,982
Repayments of senior notes	(1,107)	(1,832)	(1,000)
(Repayments) proceeds from issuance of commercial paper, net	(907)	211	(376)
Change in book overdraft	50	55	(28)
Common stock repurchases	(817)	(1,573)	(2,096)
Dividends paid	(431)	(431)	(392)
Net cash used in financing activities	(2,487)	(856)	(1,914)
(Decrease) increase in cash and cash equivalents	(2,473)	(367)	1,667
Cash and cash equivalents at beginning of period	4,694	5,061	3,394
Cash and cash equivalents at end of period	2,221	4,694	5,061
Parent Company
Condensed Financial Statements, Captions [Line Items]
Net cash provided by operating activities	3,454	3,042	4,868
Cash flows from investing activities:
Acquisitions, net of cash acquired	(89)	(233)	(337)
Capital contributions to operating subsidiaries	(1,698)	(792)	(484)
Purchases of property and equipment, net	(426)	(761)	(931)
Purchases of investment securities	(16)	(17)	(63)
Proceeds from sale of investment securities	0	41	468
Maturities of investment securities	32	67	30
Other	(50)	0	0
Net cash used in investing activities	(2,247)	(1,695)	(1,317)
Cash flows from financing activities:
Proceeds from issuance of senior notes, net	2,225	2,537	1,976
Repayments of senior notes	(1,107)	(1,832)	(1,000)
(Repayments) proceeds from issuance of commercial paper, net	(907)	211	(376)
Repayment of term loan	0	(500)	(2,000)
Change in book overdraft	(5)	2	5
Common stock repurchases	(817)	(1,573)	(2,096)
Dividends paid	(431)	(431)	(392)
Proceeds from stock option exercises and other	(86)	(125)	40
Net cash used in financing activities	(1,128)	(1,711)	(3,843)
(Decrease) increase in cash and cash equivalents	79	(364)	(292)
Cash and cash equivalents at beginning of period	250	614	906
Cash and cash equivalents at end of period	$ 329	$ 250	$ 614