| Schedule of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis | Financial assets (excluding cash held in operating accounts and time deposits) and liabilities measured at fair value on a recurring basis, as of the date indicated below, were presented on our Condensed Consolidated Balance Sheets as follows: 
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  |  |  | Quoted Prices in Active Markets for Identical Assets |  | Significant Other Observable Inputs |  | Little or No Market Activity Inputs |  
| As of December 31, 2020 (In thousands) | Total |  | (Level 1) |  | (Level 2) |  | (Level 3) |  
| Assets |  |  |  |  |  |  |  |  
| Cash equivalents: |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  
| Money market funds and other | $ | 795,712 |  |  | $ | 795,712 |  |  | $ | — |  |  | $ | — |  |  
|  |  |  |  |  |  |  |  |  
| U.S. Treasury securities | 15,400 |  |  | — |  |  | 15,400 |  |  | — |  |  
|  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  
| Marketable securities: |  |  |  |  |  |  |  |  
| Corporate debt securities | 418,348 |  |  | — |  |  | 418,348 |  |  | — |  |  
| Municipal securities | 39,352 |  |  | — |  |  | 39,352 |  |  | — |  |  
| Sovereign securities | 3,059 |  |  | — |  |  | 3,059 |  |  | — |  |  
| U.S. Government agency securities | 146,096 |  |  | 146,096 |  |  | — |  |  | — |  |  
| U.S. Treasury securities | 175,589 |  |  | 154,599 |  |  | 20,990 |  |  | — |  |  
|  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  
| 
Total cash equivalents and marketable securities(1)
 | 1,593,556 |  |  | 1,096,407 |  |  | 497,149 |  |  | — |  |  
| Other current assets: |  |  |  |  |  |  |  |  
| Derivative assets | 2,660 |  |  | — |  |  | 2,660 |  |  | — |  |  
| Other non-current assets: |  |  |  |  |  |  |  |  
| Executive Deferred Savings Plan | 245,673 |  |  | 188,203 |  |  | 57,470 |  |  | — |  |  
| 
Total financial assets(1)
 | $ | 1,841,889 |  |  | $ | 1,284,610 |  |  | $ | 557,279 |  |  | $ | — |  |  
| Liabilities |  |  |  |  |  |  |  |  
| Derivative liabilities | $ | (3,841) |  |  | $ | — |  |  | $ | (3,841) |  |  | $ | — |  |  
| Deferred payments | (4,400) |  |  | — |  |  | — |  |  | (4,400) |  |  
| Contingent consideration payable | (7,214) |  |  | — |  |  | — |  |  | (7,214) |  |  
|  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  
| Total financial liabilities | $ | (15,455) |  |  | $ | — |  |  | $ | (3,841) |  |  | $ | (11,614) |  |  ________________ (1) Excludes cash of $542.7 million held in operating accounts and time deposits of $160.3 million as of December 31, 2020. 
Financial assets (excluding cash held in operating accounts and time deposits) and liabilities measured at fair value on a recurring basis, as of the date indicated below, were presented on our Condensed Consolidated Balance Sheets as follows:   
 
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  |  |  | Quoted Prices in Active Markets for Identical Assets |  | Significant Other Observable Inputs |  | Little or No Market Activity Inputs |  
| As of June 30, 2020 (In thousands) | Total |  | (Level 1) |  | (Level 2) |  | (Level 3) |  
| Assets |  |  |  |  |  |  |  |  
| Cash equivalents: |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  
| Money market funds and other | $ | 694,950 |  |  | $ | 694,950 |  |  | $ | — |  |  | $ | — |  |  
|  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  
| Marketable securities: |  |  |  |  |  |  |  |  
| Corporate debt securities | 381,957 |  |  | — |  |  | 381,957 |  |  | — |  |  
| Municipal securities | 29,110 |  |  | — |  |  | 29,110 |  |  | — |  |  
| Sovereign securities | 2,017 |  |  | — |  |  | 2,017 |  |  | — |  |  
| U.S. Government agency securities | 106,336 |  |  | 106,336 |  |  | — |  |  | — |  |  
| U.S. Treasury securities | 181,193 |  |  | 151,210 |  |  | 29,983 |  |  | — |  |  
|  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  
| 
Total cash equivalents and marketable securities(1)
 | 1,395,563 |  |  | 952,496 |  |  | 443,067 |  |  | — |  |  
| Other current assets: |  |  |  |  |  |  |  |  
| Derivative assets | 2,077 |  |  | — |  |  | 2,077 |  |  | — |  |  
| Other non-current assets: |  |  |  |  |  |  |  |  
| Executive Deferred Savings Plan | 213,487 |  |  | 166,000 |  |  | 47,487 |  |  | — |  |  
| 
Total financial assets(1)
 | $ | 1,611,127 |  |  | $ | 1,118,496 |  |  | $ | 492,631 |  |  | $ | — |  |  
| Liabilities |  |  |  |  |  |  |  |  
| Derivative liabilities | $ | (1,410) |  |  | $ | — |  |  | $ | (1,410) |  |  | $ | — |  |  
| Deferred payments | (6,750) |  |  | — |  |  | — |  |  | (6,750) |  |  
| Contingent consideration payable | (15,513) |  |  | — |  |  | — |  |  | (15,513) |  |  
|  |  |  |  |  |  |  |  |  
| Total financial liabilities | $ | (23,673) |  |  | $ | — |  |  | $ | (1,410) |  |  | $ | (22,263) |  | ________________ (1) Excludes cash of $460.8 million held in operating accounts and time deposits of $78.7 million as of June 30, 2020. |