Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash provided by operating activities
Net income	$ 532	$ 496	$ 412
Non-cash charges to net income:
Depreciation and amortization	209	196	194
Mechanical stores expense	57	57	57
Deferred income taxes	67	(5)	(6)
Write-off of impaired assets			10
Gain on sale of plant			(10)
Charge for fair value markup of acquired inventory	9		10
Other	39	44	39
Changes in working capital:
Accounts receivable and prepaid expenses	(44)	(131)	(29)
Inventories	(34)	(19)	9
Accounts payable and accrued liabilities	(49)	127	30
Margin accounts	6	15	(34)
Other	(23)	(9)	4
Cash provided by operating activities	769	771	686
Cash used for investing activities
Payments for acquisitions, net of cash acquired of $-, $4, and $16, respectively	(17)	(407)	(434)
Capital expenditures and mechanical stores purchases	(314)	(284)	(280)
Investment in non-consolidated affiliate		(2)
Short-term investments	(3)	1	27
Proceeds from disposal of plants and properties	8	3	38
Cash used for investing activities	(326)	(689)	(649)
Cash used for financing activities
Proceeds from borrowings	1,144	1,000	1,388
Payments on debt	(1,240)	(874)	(1,366)
Debt issuance costs		(6)
Repurchase of common stock	(123)	(8)	(41)
Issuances of common stock for share-based compensation, net of settlements	9	29	21
Dividends paid (including to non-controlling interests)	(165)	(141)	(126)
Excess tax benefit on share-based compensation			8
Cash used for financing activities	(375)		(116)
Effects of foreign exchange rate changes on cash	15	(4)	(67)
Increase (decrease) in cash and cash equivalents	83	78	(146)
Cash and cash equivalents, beginning of period	512	434	580
Cash and cash equivalents, end of period	$ 595	$ 512	$ 434