Goodwill and Other Intangible Assets - Other Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	$ 1,290	$ 1,167
Acquisitions	29	126
Reclassifications	0
Other	(12)	(3)
Ending balance	1,307	1,290	$ 1,167
Finite-lived Intangible Assets, Accumulated Amortization [Roll Forward]
Accumulated amortization, beginning balance	612	493
Current year amortization	122	122	98
Reclassifications	0	0
Other (primarily Fx)	(5)	(3)
Accumulated amortization, ending balance	729	612	493
Net definite-lived intangibles	578	678
Databases and software
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	561	554
Acquisitions	0	3
Reclassifications	78
Other	(10)	4
Ending balance	629	561	554
Finite-lived Intangible Assets, Accumulated Amortization [Roll Forward]
Accumulated amortization, beginning balance	240	187
Current year amortization	73	52
Reclassifications	22	1
Other (primarily Fx)	(4)	0
Accumulated amortization, ending balance	331	240	187
Net definite-lived intangibles	298	321
Content
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	139	139
Acquisitions	0	0
Reclassifications	0
Other	0	0
Ending balance	139	139	139
Finite-lived Intangible Assets, Accumulated Amortization [Roll Forward]
Accumulated amortization, beginning balance	115	101
Current year amortization	14	14
Reclassifications	0	0
Other (primarily Fx)	0	0
Accumulated amortization, ending balance	129	115	101
Net definite-lived intangibles	10	24
Customer relationships
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	346	347
Acquisitions	0	0
Reclassifications	10
Other	(1)	(1)
Ending balance	355	346	347
Finite-lived Intangible Assets, Accumulated Amortization [Roll Forward]
Accumulated amortization, beginning balance	126	106
Current year amortization	23	21
Reclassifications	4	0
Other (primarily Fx)	0	(1)
Accumulated amortization, ending balance	153	126	106
Net definite-lived intangibles	202	220
Tradenames
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	50	50
Acquisitions	0	0
Reclassifications	5
Other	(1)	0
Ending balance	54	50	50
Finite-lived Intangible Assets, Accumulated Amortization [Roll Forward]
Accumulated amortization, beginning balance	45	42
Current year amortization	3	3
Reclassifications	1	0
Other (primarily Fx)	(1)	0
Accumulated amortization, ending balance	48	45	42
Net definite-lived intangibles	6	5
Other intangibles
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	194	77
Acquisitions	29	123
Reclassifications	(93)
Other	0	(6)
Ending balance	130	194	77
Finite-lived Intangible Assets, Accumulated Amortization [Roll Forward]
Accumulated amortization, beginning balance	86	57
Current year amortization	9	32
Reclassifications	(27)	(1)
Other (primarily Fx)	0	(2)
Accumulated amortization, ending balance	68	86	$ 57
Net definite-lived intangibles	$ 62	$ 108