Summary of Accounting Policies - Error Correction, Cash Flows (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Operating Activities
Net income (loss)	$ 78	$ 66	$ 18	$ 203
Net cash provided by (used by) operating activities			64	37
Investing Activities
Net cash used by investing activities			(466)	(149)
Financing Activities
Proceeds from term loans and notes			171	12
Repayments of term loans and notes			(278)	(35)
Retirement of long-term debt				0
Borrowings on revolving lines of credit			6,804	4,051
Payments on revolving lines of credit			(6,548)	(4,074)
Net increase (decrease) in revolver borrowings				0
Issuance (repurchase) of common shares			(2)	(2)
Cash dividends			(20)	(39)
Debt issuance cost of long-term debt				0
Purchase of common stock under the share repurchase program				0
Net increase (decrease) in bank overdrafts			(12)	(5)
Net increase (decrease) in short-term borrowings secured by accounts receivable				150
Other			1	(2)
Distributions to noncontrolling interest partners			(20)	(44)
Net cash provided by (used by) financing activities			93	12
Effect of foreign exchange rate changes on cash, cash equivalents and restricted cash			2	(15)
Increase (decrease) in cash, cash equivalents and restricted cash			(307)	(115)
Cash, cash equivalents and restricted cash, beginning of period			702	318
Cash, cash equivalents and restricted cash, end of period	$ 395	203	$ 395	203
As Reported
Operating Activities
Net income (loss)		63		201
Net cash provided by (used by) operating activities				37
Investing Activities
Net cash used by investing activities				(149)
Financing Activities
Proceeds from term loans and notes				0
Repayments of term loans and notes				0
Retirement of long-term debt				(17)
Borrowings on revolving lines of credit				0
Payments on revolving lines of credit				0
Net increase (decrease) in revolver borrowings				(29)
Issuance (repurchase) of common shares				(2)
Cash dividends				(39)
Debt issuance cost of long-term debt				(2)
Purchase of common stock under the share repurchase program				0
Net increase (decrease) in bank overdrafts				(5)
Net increase (decrease) in short-term borrowings secured by accounts receivable				150
Other				0
Distributions to noncontrolling interest partners				(44)
Net cash provided by (used by) financing activities				12
Effect of foreign exchange rate changes on cash, cash equivalents and restricted cash				(15)
Increase (decrease) in cash, cash equivalents and restricted cash				(115)
Cash, cash equivalents and restricted cash, beginning of period				318
Cash, cash equivalents and restricted cash, end of period		203		203
Reclasses
Operating Activities
Net income (loss)		0		0
Net cash provided by (used by) operating activities				0
Investing Activities
Net cash used by investing activities				0
Financing Activities
Proceeds from term loans and notes				0
Repayments of term loans and notes				(17)
Retirement of long-term debt				17
Borrowings on revolving lines of credit				0
Payments on revolving lines of credit				0
Net increase (decrease) in revolver borrowings				0
Issuance (repurchase) of common shares				0
Cash dividends				0
Debt issuance cost of long-term debt				2
Purchase of common stock under the share repurchase program				0
Net increase (decrease) in bank overdrafts				0
Net increase (decrease) in short-term borrowings secured by accounts receivable				0
Other				(2)
Distributions to noncontrolling interest partners				0
Net cash provided by (used by) financing activities				0
Effect of foreign exchange rate changes on cash, cash equivalents and restricted cash				0
Increase (decrease) in cash, cash equivalents and restricted cash				0
Cash, cash equivalents and restricted cash, beginning of period				0
Cash, cash equivalents and restricted cash, end of period		0		0
As Reclassified
Operating Activities
Net income (loss)		63		201
Net cash provided by (used by) operating activities				37
Investing Activities
Net cash used by investing activities				(149)
Financing Activities
Proceeds from term loans and notes				0
Repayments of term loans and notes				(17)
Retirement of long-term debt				0
Borrowings on revolving lines of credit				0
Payments on revolving lines of credit				0
Net increase (decrease) in revolver borrowings				(29)
Issuance (repurchase) of common shares				(2)
Cash dividends				(39)
Debt issuance cost of long-term debt				0
Purchase of common stock under the share repurchase program				0
Net increase (decrease) in bank overdrafts				(5)
Net increase (decrease) in short-term borrowings secured by accounts receivable				150
Other				(2)
Distributions to noncontrolling interest partners				(44)
Net cash provided by (used by) financing activities				12
Effect of foreign exchange rate changes on cash, cash equivalents and restricted cash				(15)
Increase (decrease) in cash, cash equivalents and restricted cash				(115)
Cash, cash equivalents and restricted cash, beginning of period				318
Cash, cash equivalents and restricted cash, end of period		203		203
Revisions
Operating Activities
Net income (loss)		3		2
Net cash provided by (used by) operating activities				0
Investing Activities
Net cash used by investing activities				0
Financing Activities
Proceeds from term loans and notes				12
Repayments of term loans and notes				(18)
Retirement of long-term debt				0
Borrowings on revolving lines of credit				4,051
Payments on revolving lines of credit				(4,074)
Net increase (decrease) in revolver borrowings				29
Issuance (repurchase) of common shares				0
Cash dividends				0
Debt issuance cost of long-term debt				0
Purchase of common stock under the share repurchase program				0
Net increase (decrease) in bank overdrafts				0
Net increase (decrease) in short-term borrowings secured by accounts receivable				0
Other				0
Distributions to noncontrolling interest partners				0
Net cash provided by (used by) financing activities				0
Effect of foreign exchange rate changes on cash, cash equivalents and restricted cash				0
Increase (decrease) in cash, cash equivalents and restricted cash				0
Cash, cash equivalents and restricted cash, beginning of period				0
Cash, cash equivalents and restricted cash, end of period		$ 0		$ 0