Organization and Significant Accounting Policies, Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Accumulated Other Comprehensive Loss [Roll Forward]
Balance		$ 771,737	$ 743,282	$ 1,577,459
Adjustments to other comprehensive loss from purchase of noncontrolling interest of Akcea Therapeutics, Inc.		0	0	(127)
Net other comprehensive income (losses) for the year		(24,812)	(11,597)	4,219
Balance		572,887	771,737	743,282
Income tax expense included in other comprehensive loss		0	0	0
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Loss [Roll Forward]
Balance		(32,668)	(21,071)	(25,290)
Balance		(57,480)	(32,668)	(21,071)
Unrealized Gains (Losses) on Securities [Member]
Accumulated Other Comprehensive Loss [Roll Forward]
Other comprehensive loss before reclassifications, net of tax	[1]	(24,395)	(11,486)	3,729
Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Loss [Roll Forward]
Other comprehensive loss before reclassifications, net of tax		$ (417)	$ (111)	$ 617

[1] We did not have tax expense included in our other comprehensive loss for the years ended December 31, 2022, 2021 and 2020.