XML 47 R36.htm IDEA: XBRL DOCUMENT v3.21.2
Investments, Summary of Investments (Details) - USD ($)
$ in Thousands
6 Months Ended 12 Months Ended
Jun. 30, 2021
Dec. 31, 2020
Summary of Investments [Abstract]    
Cost $ 1,516,288 $ 1,533,544
Gross unrealized gains 21,073 24,515
Gross unrealized losses (2,080) (2,821)
Estimated fair value 1,535,281 1,555,238
Available-for-sale Securities [Member]    
Summary of Investments [Abstract]    
Cost [1] 1,496,514 1,513,770
Gross unrealized gains 4,366 8,577
Gross unrealized losses (629) (140)
Estimated fair value 1,500,251 1,522,207
Available-for-sale Securities [Member] | Securities with Maturity of One Year or Less [Member]    
Summary of Investments [Abstract]    
Cost [1] 874,480 1,025,454
Gross unrealized gains 1,979 2,977
Gross unrealized losses (62) (71)
Estimated fair value 876,397 1,028,360
Available-for-sale Securities [Member] | Securities with Maturity of More than One Year [Member]    
Summary of Investments [Abstract]    
Cost [1] 622,034 488,316
Gross unrealized gains 2,387 5,600
Gross unrealized losses (567) (69)
Estimated fair value 623,854 493,847
Corporate Debt Securities [Member] | Securities with Maturity of One Year or Less [Member]    
Summary of Investments [Abstract]    
Cost [1],[2] 463,247 514,182
Gross unrealized gains 1,577 2,194
Gross unrealized losses (38) (41)
Estimated fair value 464,786 516,335
Corporate Debt Securities [Member] | Securities with Maturity of More than One Year [Member]    
Summary of Investments [Abstract]    
Cost [1] 390,651 325,079
Gross unrealized gains 2,091 4,941
Gross unrealized losses (294) (40)
Estimated fair value 392,448 329,980
Debt Securities Issued by U.S. Government Agencies [Member] | Securities with Maturity of One Year or Less [Member]    
Summary of Investments [Abstract]    
Cost [1] 65,610 94,234
Gross unrealized gains 164 354
Gross unrealized losses (2) (2)
Estimated fair value 65,772 94,586
Debt Securities Issued by U.S. Government Agencies [Member] | Securities with Maturity of More than One Year [Member]    
Summary of Investments [Abstract]    
Cost [1] 71,619 80,099
Gross unrealized gains 1 185
Gross unrealized losses (127) (9)
Estimated fair value 71,493 80,275
Debt Securities Issued by the U.S. Treasury [Member] | Securities with Maturity of One Year or Less [Member]    
Summary of Investments [Abstract]    
Cost [1],[2] 173,305 307,576
Gross unrealized gains 47 233
Gross unrealized losses (5) (9)
Estimated fair value 173,347 307,800
Debt Securities Issued by the U.S. Treasury [Member] | Securities with Maturity of More than One Year [Member]    
Summary of Investments [Abstract]    
Cost [1] 88,192 50,318
Gross unrealized gains 275 383
Gross unrealized losses (72) (4)
Estimated fair value 88,395 50,697
Debt Securities Issued by States of the U.S. and Political Subdivisions of the States [Member] | Securities with Maturity of One Year or Less [Member]    
Summary of Investments [Abstract]    
Cost [1] 167,235 104,271
Gross unrealized gains 191 196
Gross unrealized losses (13) (12)
Estimated fair value 167,413 104,455
Debt Securities Issued by States of the U.S. and Political Subdivisions of the States [Member] | Securities with Maturity of More than One Year [Member]    
Summary of Investments [Abstract]    
Cost [1] 65,371 31,779
Gross unrealized gains 20 91
Gross unrealized losses (52) (16)
Estimated fair value 65,339 31,854
Other Municipal Debt Securities [Member] | Securities with Maturity of One Year or Less [Member]    
Summary of Investments [Abstract]    
Cost [1] 5,083 5,191
Gross unrealized gains 0 0
Gross unrealized losses (4) (7)
Estimated fair value 5,079 5,184
Other Municipal Debt Securities [Member] | Securities with Maturity of More than One Year [Member]    
Summary of Investments [Abstract]    
Cost [1] 6,201 1,041
Gross unrealized gains 0 0
Gross unrealized losses (22) 0
Estimated fair value 6,179 1,041
Equity Securities [Member]    
Summary of Investments [Abstract]    
Cost 19,774 19,774
Gross unrealized gains 16,707 15,938
Gross unrealized losses (1,451) (2,681)
Estimated fair value 35,030 33,031
Equity Securities in Publicly Traded Company [Member]    
Summary of Investments [Abstract]    
Cost [3] 4,712 4,712
Gross unrealized gains 0 0
Gross unrealized losses (1,451) (2,681)
Estimated fair value 3,261 2,031
Equity Securities in Private Companies [Member]    
Summary of Investments [Abstract]    
Cost [4] 15,062 15,062
Gross unrealized gains 16,707 15,938
Gross unrealized losses 0 0
Estimated fair value $ 31,769 $ 31,000
[1] We hold our available-for-sale securities at amortized cost.
[2] Includes investments classified as cash equivalents on our condensed consolidated balance sheet.
[3] 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.
[4] 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.