Investment Securities (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Cost
Equity	$ 259,056	$ 262,564
Debt	720,634	613,271
Other	19,886	11,431
Total	999,576	887,266
Gains
Equity	261,966	219,658
Debt	8,859	18,090
Other	0	0
Total	270,825	237,748
Losses
Equity	(4,346)	(8,127)
Debt	(3,219)	(641)
Other	0	0
Total	(7,565)	(8,768)
Fair Value
Equity	516,676	474,095
Debt	726,274	630,720
Other	19,886	11,431
Total	$ 1,262,836	$ 1,116,246