Earnings Per Share Calculation Basic Diluted Earnings Per Share Voting Non Voting Common Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2023	Dec. 31, 2022
Earnings Per Share Diluted Other Disclosures [Abstract]
Net earnings available to common shareholders	$ 99,224	$ 198,852	$ 629,570	$ 887,063
Common Stock [Member]
Earnings Per Share Diluted Other Disclosures [Abstract]
Weighted Average Number Of Shares Outstanding Basic	19,607,788	19,607,788	19,607,788	19,607,788
Percent Weighted Average Shares Outstanding Common Stock	10.00%	10.00%	10.00%	10.00%
Net earnings available to common shareholders	$ 0	$ 0	$ 0	$ 0
Voting Common Stock dividends declared	0	0	0	(19,608)
Non-Voting Common Stock dividends declared	(8,823)	(7,059)	(22,941)	(7,059)
Undistributed earnings available to common stockholders	90,401	191,793	606,629	860,396
Undistributed earnings available to common stockholders, participating securities	$ 9,040	$ 19,179	$ 60,663	$ 86,040
Undistributed earnings per share, common stock	$ 0.46	$ 0.98	$ 3.09	$ 4.39
Dividends declared per share, distributed	0	0	0	1
Income Loss From Continuing Operations Per Basic Share, Total	$ 0.46	$ 0.98	$ 3.09	$ 5.39
Nonvoting Common Stock [Member]
Earnings Per Share Diluted Other Disclosures [Abstract]
Weighted Average Number Of Shares Outstanding Basic	176,470,092	176,470,092	176,470,092	176,470,092
Percent Weighted Average Shares Outstanding Common Stock	90.00%	90.00%	90.00%	90.00%
Net earnings available to common shareholders			$ 629,570	$ 887,063
Voting Common Stock dividends declared	$ 0	$ 0	0	(19,608)
Non-Voting Common Stock dividends declared	(8,823)	(7,059)	(22,941)	(7,059)
Undistributed earnings available to common stockholders	90,401	191,793	606,629	860,396
Undistributed earnings available to common stockholders, participating securities	$ 81,361	$ 172,614	$ 545,966	$ 774,356
Undistributed earnings per share, common stock	$ 0.46	$ 0.98	$ 3.09	$ 4.39
Dividends declared per share, distributed	0.05	0.04	0.13	0.04
Income Loss From Continuing Operations Per Basic Share, Total	$ 0.51	$ 1.02	$ 3.22	$ 4.43
Nonvoting Common Stock [Member] | Common Stock [Member]
Earnings Per Share Diluted Other Disclosures [Abstract]
Weighted Average Number Of Shares Outstanding Basic	196,077,880	196,077,880	196,077,880	196,077,880
Net earnings available to common shareholders	$ 0	$ 0	$ 0	$ 0