Federal Income Taxes - Schedule of Total Federal Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Taxes (benefits) on earnings from continuing operations:
Current	$ 42,829	$ (275)	$ 58,834
Deferred	3,747	20,031	(25,294)
Taxes on earnings from continuing operations	46,576	19,756	33,540
Taxes (benefits) on components of stockholders' equity	(47,706)	89,135	25,817
Total Federal income taxes	(1,131)	108,084	59,357
Net unrealized gains and losses on securities available-for-sale
Taxes (benefits) on earnings from continuing operations:
Taxes (benefits) on components of stockholders' equity	(51,177)	92,528	26,836
Foreign currency translation adjustments
Taxes (benefits) on earnings from continuing operations:
Taxes (benefits) on components of stockholders' equity	(4)	4	139
Change in benefit plan liability
Taxes (benefits) on earnings from continuing operations:
Taxes (benefits) on components of stockholders' equity	3,474	(3,398)	(1,158)
Change in accounting
Taxes (benefits) on earnings from continuing operations:
Taxes (benefits) on components of stockholders' equity	$ 0	$ (806)	$ 0