Note 2 - Restatement of Previously Issued Consolidated Financial Statements - Financial Statement Corrections (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended			6 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2025	Jun. 30, 2025	Mar. 31, 2025	Jun. 30, 2025	Sep. 30, 2025	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Deferred tax assets, net	$ 1,201,090	$ 1,210,033	$ 1,217,840	$ 1,210,033	$ 1,201,090	$ 1,182,883	$ 1,225,565
Total assets	4,107,222	3,872,262	3,705,143	3,872,262	4,107,222	4,194,199	3,515,822
Deferred tax liabilities	91,436	92,150	92,764	92,150	91,436	90,480	93,367
Total liabilities	729,881	662,292	631,514	662,292	729,881	662,702	564,697
Retained earnings	2,514,921	2,411,079	2,351,994	2,411,079	2,514,921	2,609,651	2,292,819
Total stockholders’ equity	3,377,341	3,209,970	3,073,629	3,209,970	3,377,341	3,531,497	2,951,125	$ 2,049,939
Total liabilities and stockholders’ equity	4,107,222	3,872,262	3,705,143	3,872,262	4,107,222	4,194,199	3,515,822
Income tax benefit, net	25,809	41,969	38,838	80,807	106,616	144,733	(1,019,146)	78,467
Net income	$ 179,766	$ 135,009	$ 135,052	$ 270,061	$ 449,827	$ 621,483	$ 1,592,058	$ 427,374
Basic (in dollars per share)	$ 3.75	$ 2.82	$ 2.82	$ 5.64	$ 9.4	$ 12.94	$ 32.76	$ 8.98
Diluted (in dollars per share)	$ 3.74	$ 2.81	$ 2.81	$ 5.62	$ 9.37	$ 12.86	$ 32.6	$ 8.76
Net income	$ 179,766	$ 135,009	$ 135,052	$ 270,061	$ 449,827	$ 621,483	$ 1,592,058	$ 427,374
Balance	3,209,970	3,073,629	2,951,125	2,951,125	2,951,125	2,951,125	2,049,939	1,668,602
Comprehensive income	180,754	154,642	140,239	294,881	475,635	654,842	1,570,609	423,389
Deferred taxes, net						39,694	(1,108,269)	5,865
Retained Earnings [Member]
Total stockholders’ equity	2,514,921	2,411,079	2,351,994	2,411,079	2,514,921	2,609,651	2,292,819	947,064
Net income	179,766	135,009	135,052			621,483	1,592,058	427,374
Net income	179,766	135,009	135,052			621,483	1,592,058	427,374
Balance	2,411,079	2,351,994	2,292,819	2,292,819	2,292,819	2,292,819	947,064	$ 716,403
Previously Reported [Member]
Deferred tax assets, net	1,300,260	1,309,981	1,318,457	1,309,981	1,300,260		1,326,840
Total assets	4,206,392	3,972,210	3,805,760	3,972,210	4,206,392		3,617,097
Deferred tax liabilities	0	0	0	0	0		0
Total liabilities	638,445	570,142	538,750	570,142	638,445		471,330
Retained earnings	2,705,527	2,603,177	2,545,375	2,603,177	2,705,527		2,487,461
Total stockholders’ equity	3,567,947	3,402,068	3,267,010	3,402,068	3,567,947		3,145,767
Total liabilities and stockholders’ equity	4,206,392	3,972,210	3,805,760	3,972,210	4,206,392		3,617,097
Income tax benefit, net	27,301	43,252	40,099	83,351	110,652		(1,213,788)
Net income	$ 178,274	$ 133,726	$ 133,791	$ 267,517	$ 445,791		$ 1,786,700
Basic (in dollars per share)	$ 3.72	$ 2.79	$ 2.8	$ 5.59	$ 9.31		$ 36.76
Diluted (in dollars per share)	$ 3.71	$ 2.78	$ 2.79	$ 5.57	$ 9.28		$ 36.59
Net income	$ 178,274	$ 133,726	$ 133,791	$ 267,517	$ 445,791		$ 1,786,700
Balance	3,402,068	3,267,010	3,145,767	3,145,767	3,145,767	3,145,767
Comprehensive income	179,262	153,359	138,978	292,337	471,599		1,765,251
Deferred taxes, net							(1,302,911)
Previously Reported [Member] | Retained Earnings [Member]
Total stockholders’ equity							2,487,461
Net income							1,786,700
Net income							1,786,700
Balance			2,487,461	2,487,461	2,487,461	2,487,461
Revision of Prior Period, Error Correction, Adjustment [Member]
Deferred tax assets, net	(99,170)	(99,948)	(100,617)	(99,948)	(99,170)		(101,275)
Total assets	(99,170)	(99,948)	(100,617)	(99,948)	(99,170)		(101,275)
Deferred tax liabilities	91,436	92,150	92,764	92,150	91,436		93,367
Total liabilities	91,436	92,150	92,764	92,150	91,436		93,367
Retained earnings	(190,606)	(192,098)	(193,381)	(192,098)	(190,606)		(194,642)
Total stockholders’ equity	(190,606)	(192,098)	(193,381)	(192,098)	(190,606)		(194,642)
Total liabilities and stockholders’ equity	(99,170)	(99,948)	(100,617)	(99,948)	(99,170)		(101,275)
Income tax benefit, net	(1,492)	(1,283)	(1,261)	(2,544)	(4,036)		194,642
Net income	$ 1,492	$ 1,283	$ 1,261	$ 2,544	$ 4,036		$ (194,642)
Basic (in dollars per share)	$ 0.03	$ 0.03	$ 0.02	$ 0.05	$ 0.09		$ (4)
Diluted (in dollars per share)	$ 0.03	$ 0.03	$ 0.02	$ 0.05	$ 0.09		$ (3.99)
Net income	$ 1,492	$ 1,283	$ 1,261	$ 2,544	$ 4,036		$ (194,642)
Balance	(192,098)	(193,381)	(194,642)	(194,642)	(194,642)	(194,642)
Comprehensive income	$ 1,492	$ 1,283	1,261	2,544	4,036		(194,642)
Deferred taxes, net							194,642
Revision of Prior Period, Error Correction, Adjustment [Member] | Retained Earnings [Member]
Total stockholders’ equity							(194,642)
Net income							(194,642)
Net income							$ (194,642)
Balance			$ (194,642)	$ (194,642)	$ (194,642)	$ (194,642)