Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Comprehensive income (loss) (pretax):
Pretax earnings (loss)	$ 246,217	$ 358,048	$ 502,609	$ 696,743
Comprehensive income (loss) (tax effect):
Income tax expense	(59,419)	(84,540)	(120,394)	(166,397)
Comprehensive income (loss) (net of tax):
Earnings available to common stockholders	186,798	273,508	382,215	530,346
Other comprehensive income (loss):
Foreign currency translation (pretax)	421	2,849	217	2,380
Foreign currency translation (tax effect)	0		0
Foreign currency translation (net of tax)	421	2,849	217	2,380
Unrealized gain (loss) on investments (pretax)	4,014	16,867	11,479	8,676
Unrealized gain (loss) on investments (tax effect)	(18)	(3,570)	(2,034)	(1,629)
Unrealized gain (loss) on investments (net of tax)	4,032	13,297	9,445	7,047
Change in fair value of cash flow hedges (pre-tax)	2,312	4,418	214	9,511
Change in fair value of cash flow hedges (tax effect)	(616)	(1,085)	(5)	(2,336)
Change in fair value of cash flow hedges (net of tax)	1,696	3,333	209	7,175
Amounts reclassified into earnings on hedging activities (pre tax)	9,479	1,345	10,904	2,495
Amounts reclassified into earnings on hedging activities (tax effect)	(2,376)	(330)	(2,726)	(612)
Amounts reclassified into earnings on hedging activities (net of tax)	7,103	1,015	8,178	1,883
Other Comprehensive Income (Loss), before Tax	10,760	16,643	22,380	13,312
Other Comprehensive Income (Loss), Tax	1,742	2,815	4,765	3,353
Total other comprehensive income (loss) (net of tax)	9,018	13,828	17,615	9,959
Total comprehensive income (loss) (pretax)	235,457	341,405	480,229	710,055
Total comprehensive income (loss) (tax effect)	(57,677)	(81,725)	(115,629)	(169,750)
Total comprehensive income (loss) (net of tax)	$ 177,780	$ 259,680	$ 364,600	$ 540,305