CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Common Stock.	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Total
Balance at Dec. 31, 2020	$ 7	$ 1,047,052	$ 2,342,329	$ 3,389,388
Balance (in shares) at Dec. 31, 2020	70,906
Changes in stockholders' equity
Net income			1,003,490	1,003,490
Stock based compensation		36,337		36,337
Stock based compensation (in shares)	1,326
Issuance of common stock in settlement of director fees		200		200
Issuance of common stock in settlement of director fees (in shares)	3
Common stock dividends			(52,896)	(52,896)
Repurchase of common stock	$ (1)	(958,193)		(958,194)
Repurchase of common stock (in shares)	(15,368)
Balance at Dec. 31, 2021	$ 6	125,396	3,292,923	3,418,325
Balance (in shares) at Dec. 31, 2021	56,867
Changes in stockholders' equity
Net income			475,507	475,507
Stock based compensation		37,719		37,719
Stock based compensation (in shares)	905
Issuance of common stock in settlement of director fees		205		205
Issuance of common stock in settlement of director fees (in shares)	4
Common stock dividends			(54,621)	(54,621)
Repurchase of common stock	$ (1)	(163,320)	(242,765)	(406,086)
Repurchase of common stock (in shares)	(7,788)
Balance at Dec. 31, 2022	$ 5		3,471,044	3,471,049
Balance (in shares) at Dec. 31, 2022	49,988
Changes in stockholders' equity
Net income			144,656	144,656
Stock based compensation		35,655		35,655
Stock based compensation (in shares)	1,389
Issuance of common stock in settlement of director fees		180		180
Issuance of common stock in settlement of director fees (in shares)	3
Common stock dividends			(41,446)	(41,446)
Repurchase of common stock		(11,548)	(59,943)	(71,491)
Repurchase of common stock (in shares)	(1,201)
Balance at Dec. 31, 2023	$ 5	$ 24,287	$ 3,514,311	$ 3,538,603
Balance (in shares) at Dec. 31, 2023	50,179