Clearing Operations (Narrative) (Details) kr in Millions	1 Months Ended		3 Months Ended
	Jan. 31, 2021 USD ($)	Jan. 31, 2021 SEK (kr)	Mar. 31, 2022 USD ($) fund contract	Mar. 31, 2021 USD ($)	Dec. 31, 2021 USD ($)
Clearing Operations [Line Items]
Number of member sponsored default funds (in funds) | fund			3
Regulatory			$ 8,000,000	$ 7,000,000
Default fund contributions			869,000,000
Default fund contributions and margin deposits			13,902,000,000
Payments for default funds and margin deposits			10,647,000,000	12,197,000,000
Proceeds from default funds and margin deposits			10,275,000,000	$ 12,002,000,000
Liability due to market default			0
Liability Waterfall
Clearing Operations [Line Items]
Junior capital, cash deposits and pledged assets			42,000,000
Senior capital, cash deposits and pledged assets			23,000,000
Committed capital			67,000,000
Utilize as capital resources
Clearing Operations [Line Items]
Default fund contributions			764,000,000
Utilize as member posted surplus balance
Clearing Operations [Line Items]
Default fund contributions			105,000,000
Nasdaq clearing members cash contributions
Clearing Operations [Line Items]
Default fund contributions			736,000,000
Default fund contributions and margin deposits			6,570,000,000		$ 5,911,000,000
Restricted cash and equivalents
Clearing Operations [Line Items]
Currency translation adjustment			160,000,000
Investments
Clearing Operations [Line Items]
Currency translation adjustment			$ 37,000,000
Minimum
Clearing Operations [Line Items]
Reverse purchase agreements, maturity range			1 day
Maximum
Clearing Operations [Line Items]
Reverse purchase agreements, maturity range			20 days
Nasdaq Clearing
Clearing Operations [Line Items]
Regulatory	$ 33,000,000	kr 300
Committed capital			$ 132,000,000
Power of assessment of the clearing member's contribution to the financial markets and commodities markets default funds (as a percent)			230.00%
Contract value of resale and repurchase agreements			$ 1,000,000,000
Total number of derivative contracts cleared (in contracts) | contract			1,317,510