CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Millions	Total	Common Stock	Additional Paid In Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Common Stock Held In Treasury
Beginning Balance at Dec. 31, 2020	$ 20,302	$ 206	$ 5,945	$ (12)	$ 14,170	$ (7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	1,584				1,584
Common stock dividends declared	(1,065)				(1,065)
Other Comprehensive Income (Loss)	(3)			(3)
Common Stock Issued Under Stock Plans	9		9
Change in Treasury Stock - Stock Compensation Plans, Net	(12)		(2)			(10)
Restricted Stock and Restricted Stock Units, Net	0		(1)			1
Stock-Based Compensation Expenses	66		66
Treasury Stock Issued as Compensation	0
Ending Balance at Jun. 30, 2021	20,881	206	6,017	(15)	14,689	(16)
Beginning Balance at Mar. 31, 2021	20,762	206	5,979	(14)	14,606	(15)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	907				907
Common stock dividends declared	(824)				(824)
Other Comprehensive Income (Loss)	(1)			(1)
Common Stock Issued Under Stock Plans	9		9
Change in Treasury Stock - Stock Compensation Plans, Net	(3)		(2)			(1)
Restricted Stock and Restricted Stock Units, Net	0
Stock-Based Compensation Expenses	31		31
Treasury Stock Issued as Compensation	0
Ending Balance at Jun. 30, 2021	20,881	206	6,017	(15)	14,689	(16)
Beginning Balance at Dec. 31, 2021	22,180	206	6,087	(12)	15,919	(20)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	2,628				2,628
Common stock dividends declared	(2,519)				(2,519)
Other Comprehensive Income (Loss)	0			0
Common Stock Issued Under Stock Plans	13		13
Change in Treasury Stock - Stock Compensation Plans, Net	(55)		(35)			(20)
Restricted Stock and Restricted Stock Units, Net	0		(2)			2
Stock-Based Compensation Expenses	65		65
Treasury Stock Issued as Compensation	0
Ending Balance at Jun. 30, 2022	22,312	206	6,128	(12)	16,028	(38)
Beginning Balance at Mar. 31, 2022	21,540	206	6,095	(13)	15,283	(31)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	2,238				2,238
Common stock dividends declared	(1,493)				(1,493)
Other Comprehensive Income (Loss)	1			1
Common Stock Issued Under Stock Plans	13		13
Change in Treasury Stock - Stock Compensation Plans, Net	(17)		(11)			(6)
Restricted Stock and Restricted Stock Units, Net	0		1			(1)
Stock-Based Compensation Expenses	30		30
Treasury Stock Issued as Compensation	0
Ending Balance at Jun. 30, 2022	$ 22,312	$ 206	$ 6,128	$ (12)	$ 16,028	$ (38)