Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2019		Sep. 30, 2019		Jun. 30, 2019		Mar. 31, 2019		Dec. 31, 2018		Sep. 30, 2018		Jun. 30, 2018		Mar. 31, 2018		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Numerator for Basic and Diluted Earnings per Share - [Abstract]
Net Income	$ 636,521		$ 615,122		$ 847,841		$ 635,426		$ 892,768		$ 1,190,952		$ 696,731		$ 638,589		$ 2,734,910	$ 3,419,040	$ 2,582,579
Denominator for Basic Earnings per Share - [Abstract]
Weighted Average Shares	578,219		577,839		577,460		577,207		577,035		577,254		576,135		575,775		577,670	576,578	574,620
Denominator for Diluted Earnings per Share - [Abstract]
Adjusted Diluted Weighted Average Shares	580,849		581,271		580,247		580,222		580,288		581,559		580,375		579,726		580,777	580,441	578,693
Antidilutive Securities Excluded from Computation of Earnings Per Share [Abstract]
Anti-dilutive Securities excluded from Diluted Earnings Per Share Calculation																	6,100	600	2,600
Net Income (Loss) Per Share [Abstract]
Basic	$ 1.10	[1]	$ 1.06	[1]	$ 1.47	[1]	$ 1.10	[1]	$ 1.55	[1]	$ 2.06	[1]	$ 1.21	[1]	$ 1.11	[1]	$ 4.73	$ 5.93	$ 4.49
Diluted	$ 1.10	[1]	$ 1.06	[1]	$ 1.46	[1]	$ 1.10	[1]	$ 1.54	[1]	$ 2.05	[1]	$ 1.20	[1]	$ 1.10	[1]	$ 4.71	$ 5.89	$ 4.46
Stock Options and Sars [Member]
Potential Dilutive Common Shares -[Abstract]
Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangments																	258	1,137	1,466
Restricted Stock/Units and Performance Units/Stock [Member]
Potential Dilutive Common Shares -[Abstract]
Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangments																	2,849	2,726	2,607

[1] The sum of quarterly net income per share may not agree with total year net income per share as each quarterly computation is based on the weighted average of common shares outstanding.