Earnings Per Share Calculation Basic Diluted Earnings Per Share Voting Non Voting Common Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended	9 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Sep. 30, 2024	Dec. 31, 2024	Dec. 31, 2023
Earnings Per Share Diluted Other Disclosures [Abstract]
Percent Weighted Average Shares Outstanding Common Stock	10.00%	10.00%		10.00%	10.00%
Net earnings available to common shareholders	$ 67,166	$ 99,224		$ 449,381	$ 629,570
Non-Voting Common Stock dividends declared				(26,471)	(22,941)
Undistributed earnings available to common stockholders				$ 42,291	$ 60,663
Undistributed earnings per share, common stock				$ 2.16	$ 3.09
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%
Non-Voting Common Stock dividends declared	$ (8,824)	$ (8,823)
Undistributed earnings available to common stockholders	58,342	90,401		$ 422,910	$ 606,629
Undistributed earnings available to common stockholders, participating securities	$ 5,834	$ 9,040
Undistributed earnings per share, common stock	$ 0.3	$ 0.46
Income Loss From Continuing Operations Per Basic Share, Total	$ 0.3	$ 0.46	$ 2.16	$ 2.16	$ 3.09
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	$ 67,166	$ 99,224		$ 449,381	$ 629,570
Non-Voting Common Stock dividends declared	(8,824)	(8,823)		(26,471)	(22,941)
Undistributed earnings available to common stockholders	58,342	90,401		422,910	606,629
Undistributed earnings available to common stockholders, participating securities	$ 52,508	$ 81,361		$ 380,619	$ 545,966
Undistributed earnings per share, common stock	$ 0.3	$ 0.46		$ 2.16	$ 3.09
Dividends declared per share, distributed	0.05	0.05		0.15	0.13
Income Loss From Continuing Operations Per Basic Share, Total	$ 0.35	$ 0.51		$ 2.31	$ 3.22
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