Quarterly Operating Results (unaudited) (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Data [Line Items]
Reserve for revenues and accounts receivables					$ 35
Amortization of intangible assets	$ 27	$ 25	$ 30	$ 29	28	$ 27	$ 26	$ 26	$ 96	$ 90	$ 74
Restructuring and integration charges	14	16	26	22	47	19	25	31
Gain associated with an insurance claim for hurricane				8
Share-based compensation, excess tax benefit, amount	2	3	5	3	1	4	5	8	13	18	37
Cost incurred do to incident		3
Gain from sale and leaseback of property	72
Legal costs and gain associated with insurance claim							10
Income tax benefit associated with changes in tax return accounting method							15			15
Decrease in contingent consideration and noncash impairment						12
Loss (gain) on disposition of business					(4)
Tax Cuts and Jobs Act of 2017, income tax expense (benefit)					1
Selling, General and Administrative Expenses
Quarterly Financial Data [Line Items]
Cost incurred do to incident		(4)
Gain from sale and leaseback of property	(1)
Other Operating Income (Expense)
Quarterly Financial Data [Line Items]
Contingent consideration arrangements			6
Cost incurred do to incident		7
Gain from sale and leaseback of property	73								73
NID
Quarterly Financial Data [Line Items]
Gain on settling uncertain tax benefits			20						20
Intangible Assets
Quarterly Financial Data [Line Items]
Amortization of intangible assets	24	23	25	24	24	22	22	22	$ 96	$ 90	$ 74
Equity in Earnings of Equity Method Investees
Quarterly Financial Data [Line Items]
Amortization of intangible assets	3	2	5	5	4	5	4	4
Cost of Sales
Quarterly Financial Data [Line Items]
Restructuring and integration charges	6	7	11	11	20	10	14	12
Legal costs and gain associated with insurance claim							11
Decrease in contingent consideration and noncash impairment						(1)
Selling, General and Administrative Expenses
Quarterly Financial Data [Line Items]
Restructuring and integration charges	$ 8	$ 9	$ 15	11	$ 27	9	11	18
Gain associated with an insurance claim for hurricane				1
Other Operating Income (Expense)
Quarterly Financial Data [Line Items]
Restructuring and integration charges								$ 1
Gain associated with an insurance claim for hurricane				$ 9
Legal costs and gain associated with insurance claim							$ (1)
Decrease in contingent consideration and noncash impairment						$ 13