Nasdaq Stockholders' Equity (Schedule of Dividends Declared) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2026	Mar. 31, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Equity [Abstract]
Dividend per common share (in dollars per share)	$ 0.31	$ 0.27	$ 0.27	$ 0.58	$ 0.51
Total Amount Paid	$ 174	$ 153		$ 327