Revenue Recognition - Allowance for Doubtful Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance, Accounts receivable, allowance for credit loss	$ 47	$ 51	$ 41
Provision for doubtful accounts	26	21	8
Write-offs less recoveries	(5)	(25)	(18)
Ending balance, Accounts receivable, allowance for credit loss	68	47	51
Allowance for Credit Loss
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	43	44	21
Provision for doubtful accounts	18	17	9
Write-offs less recoveries	(9)	(18)	14
Ending balance	52	43	44
Trade Accounts Receivable
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance, Accounts receivable, allowance for credit loss	4	7	20
Provision for doubtful accounts	8	4	(1)
Write-offs less recoveries	4	(7)	(32)
Ending balance, Accounts receivable, allowance for credit loss	$ 16	$ 4	7
OpCo
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
OpCo consolidation			20
OpCo | Allowance for Credit Loss
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
OpCo consolidation			0
OpCo | Trade Accounts Receivable
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
OpCo consolidation			$ 20