Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Numerator:
Net income	$ 90,048	$ 181,222
Denominator:
Denominator for basic net earnings per share - weighted-average shares outstanding (shares)	122,923	124,737
Effect of dilutive employee stock awards (shares)	3,103	2,840
Denominator for net diluted earnings per share - weighted-average shares outstanding (shares)	126,026	127,577
Basic earnings per share (in dollars per share)	$ 0.73	$ 1.45
Diluted earnings per share (in dollars per share)	$ 0.71	$ 1.42