Earnings Per Share - Calculation of EPS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Basic earnings per share:
Net income	$ 789,976	$ 665,244	$ 2,219,239	$ 1,279,946
Weighted-average common shares outstanding (in shares)	441,526	438,090	440,486	437,547
Basic earnings per share (in dollars per share)	$ 1.79	$ 1.52	$ 5.04	$ 2.93
Diluted earnings per share:
Net income	$ 789,976	$ 665,244	$ 2,219,239	$ 1,279,946
Shares used in computation:
Weighted-average common shares outstanding (in shares)	441,526	438,090	440,486	437,547
Employee stock options (in shares)	13,562	13,462	13,360	14,349
Weighted-average number of shares (in shares)	455,088	451,552	453,846	451,896
Diluted earnings per share (in dollars per share)	$ 1.74	$ 1.47	$ 4.89	$ 2.83