Acquisitions and Divestitures - Divestitures Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Pre-tax gain (loss) on dispositions	$ 16	$ 49	$ 0
Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Pre-tax gain (loss) on dispositions	16	49
Sale | I R Webhosting Business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Pre-tax gain (loss) on dispositions	11
Gain on disposition after tax	6
Sale | Facility At East Windsor New Jersey
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Pre-tax gain (loss) on dispositions	4
Gain on disposition after tax	3
Sale | Standard & Poor's Investment Advisory Services LLC
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Pre-tax gain (loss) on dispositions	1	22
Gain on disposition after tax	$ 1	12
Sale | RigData
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Pre-tax gain (loss) on dispositions		27
Gain on disposition after tax		$ 26