Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Comprehensive income (loss) (pretax):
Pretax earnings (loss)	$ 114,318	$ 174,714
Comprehensive income (loss) (tax effect):
Income tax expense	(26,592)	(42,292)
Comprehensive income (loss) (net of tax):
Net earnings	87,726	132,422
Other comprehensive income (loss):
Foreign currency translation (pretax)	(2,917)	2,982
Foreign currency translation (tax effect)	0	0
Foreign currency translation (net of tax)	(2,917)	2,982
Unrealized gain (loss) on investments (pretax)	(58,962)	51,827
Unrealized gain (loss) on investments (tax effect)	13,463	(11,039)
Unrealized gain (loss) on investments (net of tax)	(45,499)	40,788
Change in fair value of cash flow hedges (pretax)	(705)	(1,194)
Change in fair value of cash flow hedges (tax effect)	173	293
Change in fair value of cash flow hedges (net of tax)	(532)	(901)
Amounts reclassifed into earnings on hedging activities (pretax)	747	(59)
Amounts reclassified into earnings on hedging activities (tax effect)	(183)	15
Amounts reclassified into earnings on hedging activities (net of tax)	564	(44)
Total other comprehensive income (loss) (pretax)	(61,837)	53,556
Total other comprehensive income (loss) (tax effect)	13,453	(10,731)
Total other comprehensive income (loss) (net of tax)	(48,384)	42,825
Total comprehensive income (pretax)	52,481	228,270
Total comprehensive income (tax effect)	(13,139)	(53,023)
Total comprehensive income (net of tax)	$ 39,342	$ 175,247