Deferred Revenue (Estimated Deferred Revenue) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Fiscal year ended:
2020	$ 164
2021	141
2022	21
2023	14
2024	7
2025 and thereafter	5
Total	352	$ 274
Initial Listing Revenues
Fiscal year ended:
2020	8
2021	28
2022	17
2023	10
2024	7
2025 and thereafter	5
Total	75	69
Annual Listings Revenues
Fiscal year ended:
2020	65
2021	0
2022	0
2023	0
2024	0
2025 and thereafter	0
Total	65	2
Corporate Solutions Revenues
Fiscal year ended:
2020	23
2021	23
2022	0
2023	0
2024	0
2025 and thereafter	0
Total	46	41
Information Services Revenues
Fiscal year ended:
2020	39
2021	52
2022	0
2023	0
2024	0
2025 and thereafter	0
Total	91	82
Market Technology Revenues
Fiscal year ended:
2020	25
2021	33
2022	1
2023	1
2024	0
2025 and thereafter	0
Total	60	66
Other
Fiscal year ended:
2020	4
2021	5
2022	3
2023	3
2024	0
2025 and thereafter	0
Total	$ 15	$ 14

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