Stockholders' Equity (Schedule of Classes of Capital Stock) (Details) - $ / shares |
12 Months Ended | |
|---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
|
| Preferred Stock, Shares Issued | 0 | 0 |
| Preferred Stock, Shares Outstanding | 0 | 0 |
| Public Investors (Class A Stockholders) | ||
| Equity Ownership | 88.20% | 87.80% |
| General Voting Power | 88.90% | 88.80% |
| Principal or Affiliate Members (Class B Stockholders) | ||
| Equity Ownership | 0.80% | 1.10% |
| General Voting Power | 0.00% | 0.00% |
| The MasterCard Foundation (Class A Stockholders) | ||
| Equity Ownership | 11.00% | 11.10% |
| General Voting Power | 11.10% | 11.20% |
| Class A Common Stock | ||
| Common Stock, Par Value Per Share | $ 0.0001 | $ 0.0001 |
| Common Stock, Authorized Shares | 3,000,000,000 | 3,000,000,000 |
| Class B Common Stock | ||
| Common Stock, Par Value Per Share | $ 0.0001 | $ 0.0001 |
| Common Stock, Authorized Shares | 1,200,000,000 | 1,200,000,000 |
| Preferred Stock | ||
| Preferred Stock, Par Value Per Share | $ 0.0001 | $ 0.0001 |
| Preferred Stock, Authorized Shares | 300,000,000 | 300,000,000 |