Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Treasury Stock, Common [Member]
Balance at Dec. 31, 2016	$ 13,981,581	$ 205,770	$ 5,420,385	$ (19,010)	$ 8,398,118	$ (23,682)
Net Income	2,582,579	0	0	0	2,582,579	0
Common Stock Issued Under Stock Plans	7,089	7	7,082	0	0	0
Dividends, Common Stock	$ (387,164)	0	0	0	(387,164)	0
Common Stock Dividends Declared (in dollars per share)	$ 0.670
Other Comprehensive Income (Loss)	$ (287)	0	0	(287)	0	0
Change in Treasury Stock - Stock Compensation Plans, Net	(36,743)	0	(27,348)	0	0	(9,395)
Restricted Stock and Restricted Stock Units, Net	0	11	2,552	0	0	(2,563)
Stock-Based Compensation Expenses	133,849	0	133,849	0	0	0
Treasury Stock Issued as Compensation	2,369	0	27	0	0	2,342
Balance at Dec. 31, 2017	16,283,273	205,788	5,536,547	(19,297)	10,593,533	(33,298)
Net Income	3,419,040	0	0	0	3,419,040	0
Common Stock Issued Under Stock Plans	5,620	8	5,612	0	0	0
Dividends, Common Stock	$ (469,443)	0	0	0	(469,443)	0
Common Stock Dividends Declared (in dollars per share)	$ 0.810
Other Comprehensive Income (Loss)	$ 17,939	0	0	17,939	0	0
Change in Treasury Stock - Stock Compensation Plans, Net	(48,454)	0	(35,118)	0	0	(13,336)
Restricted Stock and Restricted Stock Units, Net	0	8	(3,891)	0	0	3,883
Stock-Based Compensation Expenses	155,337	0	155,337	0	0	0
Treasury Stock Issued as Compensation	876	0	307	0	0	569
Balance at Dec. 31, 2018	19,364,188	205,804	5,658,794	(1,358)	13,543,130	(42,182)
Net Income	2,734,910	0	0	0	2,734,910	0
Common Stock Issued Under Stock Plans	(8)	1	(9)	0	0	0
Dividends, Common Stock	$ 629,169	0	0	0	629,169	0
Common Stock Dividends Declared (in dollars per share)	$ 1.083
Other Comprehensive Income (Loss)	$ (3,561)	0	0	(3,561)	0	0
Change in Treasury Stock - Stock Compensation Plans, Net	(6,853)	0	(10,637)	0	0	3,784
Restricted Stock and Restricted Stock Units, Net	0	17	(4,566)	0	0	4,549
Stock-Based Compensation Expenses	174,738	0	174,738	0	0	0
Treasury Stock Issued as Compensation	6,471	0	(845)	0	0	7,316
Balance at Dec. 31, 2019	21,640,716	205,822	5,817,475	(4,652)	15,648,604	(26,533)
Cumulative Effect of Accounting Changes	$ 0	$ 0	$ 0	$ 267	$ (267)	$ 0