XML 46 R34.htm IDEA: XBRL DOCUMENT v3.21.1
Investments, Summary of Investments (Details) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Mar. 31, 2021
Dec. 31, 2020
Summary of Investments [Abstract]    
Cost $ 1,430,181 $ 1,533,544
Gross unrealized gains 21,965 24,515
Gross unrealized losses (2,110) (2,821)
Estimated fair value 1,450,036 1,555,238
Available-for-sale Securities [Member]    
Summary of Investments [Abstract]    
Cost [1] 1,410,407 1,513,770
Gross unrealized gains 6,027 8,577
Gross unrealized losses (596) (140)
Estimated fair value 1,415,838 1,522,207
Available-for-sale Securities [Member] | Securities with Maturity of One Year or Less [Member]    
Summary of Investments [Abstract]    
Cost [1] 888,596 1,025,454
Gross unrealized gains 2,476 2,977
Gross unrealized losses (107) (71)
Estimated fair value 890,965 1,028,360
Available-for-sale Securities [Member] | Securities with Maturity of More than One Year [Member]    
Summary of Investments [Abstract]    
Cost [1] 521,811 488,316
Gross unrealized gains 3,551 5,600
Gross unrealized losses (489) (69)
Estimated fair value 524,873 493,847
Corporate Debt Securities [Member] | Securities with Maturity of One Year or Less [Member]    
Summary of Investments [Abstract]    
Cost [1],[2] 446,816 514,182
Gross unrealized gains 1,838 2,194
Gross unrealized losses (76) (41)
Estimated fair value 448,578 516,335
Corporate Debt Securities [Member] | Securities with Maturity of More than One Year [Member]    
Summary of Investments [Abstract]    
Cost [1] 325,335 325,079
Gross unrealized gains 3,108 4,941
Gross unrealized losses (245) (40)
Estimated fair value 328,198 329,980
Debt Securities Issued by U.S. Government Agencies [Member] | Securities with Maturity of One Year or Less [Member]    
Summary of Investments [Abstract]    
Cost [1] 80,703 94,234
Gross unrealized gains 292 354
Gross unrealized losses (2) (2)
Estimated fair value 80,993 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] 96,698 80,099
Gross unrealized gains 36 185
Gross unrealized losses (164) (9)
Estimated fair value 96,570 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] 234,164 307,576
Gross unrealized gains 126 233
Gross unrealized losses 0 (9)
Estimated fair value 234,290 307,800
Debt Securities Issued by the U.S. Treasury [Member] | Securities with Maturity of More than One Year [Member]    
Summary of Investments [Abstract]    
Cost [1] 59,030 50,318
Gross unrealized gains 326 383
Gross unrealized losses (35) (4)
Estimated fair value 59,321 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] 121,776 104,271
Gross unrealized gains 220 196
Gross unrealized losses (22) (12)
Estimated fair value 121,974 104,455
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] 34,515 31,779
Gross unrealized gains 81 91
Gross unrealized losses (25) (16)
Estimated fair value 34,571 31,854
Other Municipal Debt Securities [Member] | Securities with Maturity of One Year or Less [Member]    
Summary of Investments [Abstract]    
Cost [1] 5,137 5,191
Gross unrealized gains 0 0
Gross unrealized losses (7) (7)
Estimated fair value 5,130 5,184
Other Municipal Debt Securities [Member] | Securities with Maturity of More than One Year [Member]    
Summary of Investments [Abstract]    
Cost [1] 6,233 1,041
Gross unrealized gains 0 0
Gross unrealized losses (20) 0
Estimated fair value 6,213 1,041
Equity Securities [Member]    
Summary of Investments [Abstract]    
Cost 19,774 19,774
Gross unrealized gains 15,938 15,938
Gross unrealized losses (1,514) (2,681)
Estimated fair value 34,198 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 (1,514) (2,681)
Estimated fair value 3,198 2,031
Equity Securities in Private Companies [Member]    
Summary of Investments [Abstract]    
Cost [4] 15,062 15,062
Gross unrealized gains 15,938 15,938
Gross unrealized losses 0 0
Estimated fair value $ 31,000 $ 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.