Earnings Per Share - Calculation of EPS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Basic earnings per share:
Net income	$ 720,196	$ 270,650	$ 1,429,263	$ 614,702
Weighted-average common shares outstanding (in shares)	440,569	437,587	439,961	437,271
Basic earnings per share (in dollars per share)	$ 1.63	$ 0.62	$ 3.25	$ 1.41
Diluted earnings per share:
Net income	$ 720,196	$ 270,650	$ 1,429,263	$ 614,702
Shares used in computation:
Weighted-average common shares outstanding (in shares)	440,569	437,587	439,961	437,271
Employee stock options (in shares)	13,376	14,608	13,259	14,792
Weighted-average number of shares (in shares)	453,945	452,195	453,220	452,063
Diluted earnings per share (in dollars per share)	$ 1.59	$ 0.60	$ 3.15	$ 1.36