Investments, Summary of Investments (Details) $ in Thousands		9 Months Ended
		Sep. 30, 2022 USD ($) Company	Dec. 31, 2021 USD ($)
Ownership Interests in Private and Public Companies [Abstract]
Number of private companies in which there is an equity ownership interest of less than 20% | Company		8
Number of public companies in which there is an equity ownership interest of less than 20% | Company		3
Available-for-sale Securities with Maturity of One Year or Less [Abstract]
Amortized cost		$ 1,133,227	$ 612,557
Gross unrealized gains		35	792
Gross unrealized losses		(11,647)	(345)
Estimated fair value		1,121,615	613,004
Available-for-sale Securities with Maturity of More Than One Year [Abstract]
Amortized cost		600,371	638,615
Gross unrealized gains		29	471
Gross unrealized losses		(20,982)	(3,966)
Estimated fair value		579,418	635,120
Available-for-sale Securities [Abstract]
Amortized cost		1,733,598	1,251,172
Gross unrealized gains		64	1,263
Gross unrealized losses		(32,629)	(4,311)
Estimated fair value		1,701,033	1,248,124
Equity Securities [Abstract]
Amortized cost		38,212	27,512
Gross unrealized gains		17,257	23,852
Gross unrealized losses		(7,841)	(837)
Estimated fair value		47,628	50,527
Available-for-sale and Equity Securities [Abstract]
Amortized cost		1,771,810	1,278,684
Gross unrealized gains		17,321	25,115
Gross unrealized losses		(40,470)	(5,148)
Estimated fair value		1,748,661	1,298,651
Corporate Debt Securities [Member]
Available-for-sale Securities with Maturity of One Year or Less [Abstract]
Amortized cost	[1]	487,666	383,870
Gross unrealized gains		1	728
Gross unrealized losses		(5,327)	(226)
Estimated fair value		482,340	384,372
Available-for-sale Securities with Maturity of More Than One Year [Abstract]
Amortized cost		258,362	382,000
Gross unrealized gains		6	331
Gross unrealized losses		(12,654)	(2,644)
Estimated fair value		245,714	379,687
Debt Securities Issued by U.S. Government Agencies [Member]
Available-for-sale Securities with Maturity of One Year or Less [Abstract]
Amortized cost		104,987	48,493
Gross unrealized gains		12	19
Gross unrealized losses		(1,686)	(18)
Estimated fair value		103,313	48,494
Available-for-sale Securities with Maturity of More Than One Year [Abstract]
Amortized cost		28,987	72,935
Gross unrealized gains		8	0
Gross unrealized losses		(1,541)	(561)
Estimated fair value		27,454	72,374
Debt Securities Issued by the U.S. Treasury [Member]
Available-for-sale Securities with Maturity of One Year or Less [Abstract]
Amortized cost	[1]	462,475	45,424
Gross unrealized gains		22	0
Gross unrealized losses		(3,761)	(64)
Estimated fair value		458,736	45,360
Available-for-sale Securities with Maturity of More Than One Year [Abstract]
Amortized cost		298,431	137,635
Gross unrealized gains		13	139
Gross unrealized losses		(6,247)	(500)
Estimated fair value		292,197	137,274
Debt Securities Issued by States of the U.S. and Political Subdivisions of the States [Member]
Available-for-sale Securities with Maturity of One Year or Less [Abstract]
Amortized cost		72,059	134,770
Gross unrealized gains		0	45
Gross unrealized losses		(797)	(37)
Estimated fair value		71,262	134,778
Available-for-sale Securities with Maturity of More Than One Year [Abstract]
Amortized cost		14,591	39,909
Gross unrealized gains		2	1
Gross unrealized losses		(540)	(224)
Estimated fair value		14,053	39,686
Other Municipal Debt Securities [Member]
Available-for-sale Securities with Maturity of One Year or Less [Abstract]
Amortized cost		6,040
Gross unrealized gains		0
Gross unrealized losses		(76)
Estimated fair value		5,964
Available-for-sale Securities with Maturity of More Than One Year [Abstract]
Amortized cost			6,136
Gross unrealized gains			0
Gross unrealized losses			(37)
Estimated fair value			6,099
Publicly Traded Equity Securities [Member]
Equity Securities [Abstract]
Amortized cost	[2]	15,097	11,897
Gross unrealized gains		0	7,145
Gross unrealized losses		(7,841)	(837)
Estimated fair value		7,256	18,205
Available-for-sale and Equity Securities [Abstract]
Unrealized loss on equity investment		(10,900)
Privately Held Equity Securities [Member]
Equity Securities [Abstract]
Amortized cost	[3]	23,115	15,615
Gross unrealized gains		17,257	16,707
Gross unrealized losses		0	0
Estimated fair value		$ 40,372	$ 32,322

[1] Includes investments classified as cash equivalents in our condensed consolidated balance sheet.

[2] Our equity securities included in other current assets consisted of our investments in publicly traded companies. We recognize publicly traded equity securities at fair value. In the nine months ended September 30, 2022, we recognized a $10.9 million unrealized non-cash loss in our condensed consolidated statement of operations related to a decrease in the fair value of our investments in publicly traded companies.

[3] Our equity securities included in deposits and other assets consisted of our investments in privately held companies. We recognize our private company equity securities at cost minus impairments, plus or minus changes resulting from observable price changes in orderly transactions for the identical or similar investment of the same issuer.