EARNINGS PER SHARE (Computation of Basic and Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Numerator (basic and diluted):
Net income	$ 501,609	$ 300,438
Denominator:
Denominator for basic earnings per share - weighted-average shares	70,383	75,022
Effect of stock options	632	641
Denominator for diluted earnings per share - weighted-average shares and assumed conversion	71,015	75,663
Earnings per share - basic	$ 7.13	$ 4.00
Earnings per share - assuming dilution	$ 7.06	$ 3.97
Antidilutive stock options	211	349
Weighted-average exercise price per share of antidilutive stock options	$ 437.90	$ 377.41