Nasdaq Stockholders' Equity (Schedule of Dividends Declared) (Details) - USD ($) $ / shares in Units, $ in Millions |
3 Months Ended | 9 Months Ended | ||||
|---|---|---|---|---|---|---|
Sep. 30, 2025 |
Jun. 30, 2025 |
Mar. 31, 2025 |
Sep. 30, 2024 |
Sep. 30, 2025 |
Sep. 30, 2024 |
|
| Equity [Abstract] | ||||||
| Dividend per common share (in dollars per share) | $ 0.27 | $ 0.27 | $ 0.24 | $ 0.24 | $ 0.78 | $ 0.70 |
| Total Amount Paid | $ 155 | $ 155 | $ 138 | $ 448 | ||