Deferred Revenue (Estimated Deferred Revenue) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Deferred Revenue Arrangement [Line Items]
2015	$ 177
2016	62
2017	53
2018	34
2019	25
2020 and thereafter	41
Deferred revenue estimated revenue to be recognized	392		294		295
Initial Listing Revenues [Member]
Deferred Revenue Arrangement [Line Items]
2015	15
2016	13
2017	10
2018	8
2019	6
2020 and thereafter	2
Deferred revenue estimated revenue to be recognized	54		41		36
Listing of Additional Shares Revenues [Member]
Deferred Revenue Arrangement [Line Items]
2015	33
2016	25
2017	15
2018	5
Deferred revenue estimated revenue to be recognized	78		75		78
Annual Renewal and Other Revenues [Member]
Deferred Revenue Arrangement [Line Items]
2015	12
2016	1
Deferred revenue estimated revenue to be recognized	13		20		27
Technology Solutions [Member]
Deferred Revenue Arrangement [Line Items]
2015	117	[1]
2016	23	[1]
2017	28	[1]
2018	21	[1]
2019	19	[1]
2020 and thereafter	39	[1]
Deferred revenue estimated revenue to be recognized	$ 247	[1]	$ 158	[1]	$ 154	[1]

[1] The timing of recognition of our deferred Technology Solutions revenues is primarily dependent upon the completion of customization and any significant modifications made pursuant to existing Market Technology contracts and the timing of Corporate Solutions subscription-based contracts. As such, as it relates to Market Technology revenues, the timing represents our best estimate.