Summary of Significant Accounting Policies (Tax Effects of Components of Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total other comprehensive income (loss), Before-Tax Amount	$ (6,340)	$ 4,717	$ (6,507)
Total other comprehensive income (loss), Tax (Expense) Benefit	(666)	1,471	(2,096)
TOTAL OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX	(5,674)	3,246	(4,411)
Defined benefit pension plan adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total other comprehensive income (loss), Before-Tax Amount	7,230	8,665	(8,700)
Total other comprehensive income (loss), Tax (Expense) Benefit	2,001	2,444	(2,439)
TOTAL OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX	5,229	6,221	(6,261)
Foreign currency translation adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total other comprehensive income (loss), Before-Tax Amount	(3,351)	(508)	178
Total other comprehensive income (loss), Tax (Expense) Benefit	(556)	(183)	(101)
TOTAL OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX	(2,795)	(325)	279
Unrealized gain (loss) in fair value of investments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total other comprehensive income (loss), Before-Tax Amount	(10,219)	(3,440)	2,015
Total other comprehensive income (loss), Tax (Expense) Benefit	(2,111)	(790)	444
TOTAL OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX	(8,108)	(2,650)	1,571
Noncontrolling Interests
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total other comprehensive income (loss), Before-Tax Amount	(2,272)	140	230
Total other comprehensive income (loss), Tax (Expense) Benefit	0	0	0
TOTAL OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX	(2,272)	140	230
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total other comprehensive income (loss), Before-Tax Amount	(4,068)	4,577	(6,737)
Total other comprehensive income (loss), Tax (Expense) Benefit	(666)	1,471	(2,096)
TOTAL OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX	$ (3,402)	$ 3,106	$ (4,641)