Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating activities:
Net income	$ 144.9	$ 146.9
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	83.3	79.3
Deferred income taxes	23.9	44.3
Equity in net earnings of affiliates	(1.0)	(4.0)
Share-based compensation	5.8	4.8
Settlement of foreign currency derivative instruments	12.1	(49.5)
Gain on foreign currency derivative instruments	(16.5)	(33.9)
Mexican fuel excise tax credit	(9.2)	(11.7)
Changes in working capital items:
Accounts receivable	(37.2)	(16.1)
Materials and supplies	(7.5)	(2.6)
Other current assets	(22.1)	(5.3)
Accounts payable and accrued liabilities	(19.2)	(9.8)
Other, net	(16.7)	(12.8)
Net cash provided by operating activities	140.6	129.6
Investing activities:
Capital expenditures	(110.0)	(160.1)
Purchase or replacement of equipment under operating leases	(11.2)	0.0
Property investments in MSLLC	(3.9)	(4.2)
Investments in and advances to affiliates	(0.2)	(0.2)
Proceeds from disposal of property	1.4	4.7
Other, net	(0.3)	(2.6)
Net cash provided (used)	(124.2)	(162.4)
Financing activities:
Proceeds from short-term borrowings	2,609.9	2,747.8
Repayment of short-term borrowings	(2,614.0)	(2,664.9)
Repayment of long-term debt	(8.7)	(6.7)
Dividends paid	(37.1)	(35.2)
Shares repurchased	(54.0)	(55.7)
Proceeds from employee stock plans	0.4	0.0
Net cash used for financing activities	(103.5)	(14.7)
Cash and cash equivalents:
Net decrease during each period	(87.1)	(47.5)
At beginning of year	134.1	170.6
At end of period	$ 47.0	$ 123.1