Consolidating Financial Information - Condensed Consolidating Statement of Cash Flows (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash Flows from Operating Activities:
Total Cash Flows from Operating Activities	$ 237	$ 635
Cash Flows from Investing Activities:
Capital Expenditures	(711)	(656)
Asset Dispositions	13	13
Decrease (Increase) in Restricted Cash	1	(11)
Short Term Securities Acquired	(46)	(50)
Short Term Securities Redeemed	34	25
Capital Contributions and Loans Incurred	0	0
Capital Redemptions and Loans Paid	0	0
Other Transactions	2	5
Total Cash Flows from Investing Activities	(707)	(674)
Cash Flows from Financing Activities:
Short Term Debt and Overdrafts Incurred	219	72
Short Term Debt and Overdrafts Paid	(99)	(59)
Long Term Debt Incurred	4,129	1,265
Long Term Debt Paid	(4,025)	(1,469)
Common Stock Issued	9	33
Common Stock Repurchased	(200)	(82)
Common Stock Dividends Paid	(56)	(49)
Capital Contributions and Loans Incurred	0	0
Capital Redemptions and Loans Paid	0	0
Intercompany Dividends Paid	0	0
Transactions with Minority Interests in Subsidiaries	(9)	(5)
Debt Related Costs and Other Transactions	(24)	(12)
Total Cash Flows from Financing Activities	(56)	(306)
Effect of Exchange Rate Changes on Cash and Cash Equivalents	25	(102)
Net Change in Cash and Cash Equivalents	(501)	(447)
Cash and Cash Equivalents at Beginning of the Period	1,476	2,161
Less: Cash Held for Sale	0	(24)
Cash and Cash Equivalents at End of the Period	975	1,690
Parent Company
Cash Flows from Operating Activities:
Total Cash Flows from Operating Activities	(4)	326
Cash Flows from Investing Activities:
Capital Expenditures	(266)	(252)
Asset Dispositions	11	1
Decrease (Increase) in Restricted Cash	0	0
Short Term Securities Acquired	0	0
Short Term Securities Redeemed	0	0
Capital Contributions and Loans Incurred	(165)	(70)
Capital Redemptions and Loans Paid	48	12
Other Transactions	0	0
Total Cash Flows from Investing Activities	(372)	(309)
Cash Flows from Financing Activities:
Short Term Debt and Overdrafts Incurred	0	47
Short Term Debt and Overdrafts Paid	(14)	0
Long Term Debt Incurred	2,339	455
Long Term Debt Paid	(2,034)	(659)
Common Stock Issued	9	33
Common Stock Repurchased	(200)	(82)
Common Stock Dividends Paid	(56)	(49)
Capital Contributions and Loans Incurred	248	90
Capital Redemptions and Loans Paid	(148)	(40)
Intercompany Dividends Paid	0	0
Transactions with Minority Interests in Subsidiaries	0	0
Debt Related Costs and Other Transactions	(22)	(3)
Total Cash Flows from Financing Activities	122	(208)
Effect of Exchange Rate Changes on Cash and Cash Equivalents	0	0
Net Change in Cash and Cash Equivalents	(254)	(191)
Cash and Cash Equivalents at Beginning of the Period	354	674
Less: Cash Held for Sale		0
Cash and Cash Equivalents at End of the Period	100	483
Guarantor Subsidiaries
Cash Flows from Operating Activities:
Total Cash Flows from Operating Activities	17	1
Cash Flows from Investing Activities:
Capital Expenditures	(74)	(27)
Asset Dispositions	0	0
Decrease (Increase) in Restricted Cash	0	0
Short Term Securities Acquired	0	0
Short Term Securities Redeemed	0	0
Capital Contributions and Loans Incurred	0	0
Capital Redemptions and Loans Paid	0	0
Other Transactions	0	0
Total Cash Flows from Investing Activities	(74)	(27)
Cash Flows from Financing Activities:
Short Term Debt and Overdrafts Incurred	14	0
Short Term Debt and Overdrafts Paid	0	(8)
Long Term Debt Incurred	0	0
Long Term Debt Paid	0	0
Common Stock Issued	0	0
Common Stock Repurchased	0	0
Common Stock Dividends Paid	0	0
Capital Contributions and Loans Incurred	59	12
Capital Redemptions and Loans Paid	(25)	(12)
Intercompany Dividends Paid	0	0
Transactions with Minority Interests in Subsidiaries	0	0
Debt Related Costs and Other Transactions	0	0
Total Cash Flows from Financing Activities	48	(8)
Effect of Exchange Rate Changes on Cash and Cash Equivalents	1	(10)
Net Change in Cash and Cash Equivalents	(8)	(44)
Cash and Cash Equivalents at Beginning of the Period	70	89
Less: Cash Held for Sale		0
Cash and Cash Equivalents at End of the Period	62	45
Non-Guarantor Subsidiaries
Cash Flows from Operating Activities:
Total Cash Flows from Operating Activities	252	332
Cash Flows from Investing Activities:
Capital Expenditures	(375)	(382)
Asset Dispositions	2	12
Decrease (Increase) in Restricted Cash	1	(11)
Short Term Securities Acquired	(46)	(50)
Short Term Securities Redeemed	34	25
Capital Contributions and Loans Incurred	(248)	(90)
Capital Redemptions and Loans Paid	148	40
Other Transactions	2	5
Total Cash Flows from Investing Activities	(482)	(451)
Cash Flows from Financing Activities:
Short Term Debt and Overdrafts Incurred	219	72
Short Term Debt and Overdrafts Paid	(99)	(98)
Long Term Debt Incurred	1,790	810
Long Term Debt Paid	(1,991)	(810)
Common Stock Issued	0	0
Common Stock Repurchased	0	0
Common Stock Dividends Paid	0	0
Capital Contributions and Loans Incurred	106	58
Capital Redemptions and Loans Paid	(23)	0
Intercompany Dividends Paid	(24)	(19)
Transactions with Minority Interests in Subsidiaries	(9)	(5)
Debt Related Costs and Other Transactions	(2)	(9)
Total Cash Flows from Financing Activities	(33)	(1)
Effect of Exchange Rate Changes on Cash and Cash Equivalents	24	(92)
Net Change in Cash and Cash Equivalents	(239)	(212)
Cash and Cash Equivalents at Beginning of the Period	1,052	1,398
Less: Cash Held for Sale		(24)
Cash and Cash Equivalents at End of the Period	813	1,162
Consolidating Entries and Eliminations
Cash Flows from Operating Activities:
Total Cash Flows from Operating Activities	(28)	(24)
Cash Flows from Investing Activities:
Capital Expenditures	4	5
Asset Dispositions	0	0
Decrease (Increase) in Restricted Cash	0	0
Short Term Securities Acquired	0	0
Short Term Securities Redeemed	0	0
Capital Contributions and Loans Incurred	413	160
Capital Redemptions and Loans Paid	(196)	(52)
Other Transactions	0	0
Total Cash Flows from Investing Activities	221	113
Cash Flows from Financing Activities:
Short Term Debt and Overdrafts Incurred	(14)	(47)
Short Term Debt and Overdrafts Paid	14	47
Long Term Debt Incurred	0	0
Long Term Debt Paid	0	0
Common Stock Issued	0	0
Common Stock Repurchased	0	0
Common Stock Dividends Paid	0	0
Capital Contributions and Loans Incurred	(413)	(160)
Capital Redemptions and Loans Paid	196	52
Intercompany Dividends Paid	24	19
Transactions with Minority Interests in Subsidiaries	0	0
Debt Related Costs and Other Transactions	0	0
Total Cash Flows from Financing Activities	(193)	(89)
Effect of Exchange Rate Changes on Cash and Cash Equivalents	0	0
Net Change in Cash and Cash Equivalents	0	0
Cash and Cash Equivalents at Beginning of the Period	0	0
Less: Cash Held for Sale		0
Cash and Cash Equivalents at End of the Period	$ 0	$ 0