Summary of Significant Accounting Policies - Comprehensive Income (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss consists of foreign currency translation adjustments, net of tax	$ 36,550,000	$ 48,050,000
Net unrealized losses on available-for-sale investments, net of tax	7,515,000	19,976,000
Losses on currency swaps, net of gains on long-term intercompany loans	1,271,000	1,271,000
Net realized gains reclassified into current operations	(1,954,000)	(182,000)	$ 236,000
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net realized gains reclassified into current operations	$ (1,954,000)	$ (182,000)	$ 236,000