Held for Sale - Schedule of Assets Held for Sale (Details) - TRAYPORT - Disposal Group, Held-for-sale, Not Discontinued Operations $ in Millions	6 Months Ended
	Jun. 30, 2017 USD ($)
Assets held for sale:
Cash and cash equivalents	$ 6
Goodwill	331
Other intangibles, net	214
Other current and non-current assets	27
Total assets held for sale (included in prepaid expenses and other current assets)	578
Liabilities held for sale:
Deferred tax liabilities	38
Other current and non-current liabilities	19
Total liabilities held for sale (included in other current liabilities)	57
Accumulated other comprehensive loss from foreign currency translation classified as held for sale in equity	$ 89