Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Operating Activities
Net income	$ 110.8	$ 80.8	$ 81.4
Adjustments to reconcile income to net cash provided by operating activities:
Gains on sales of assets	(70.1)	(43.5)	(21.3)
Depreciation	238.5	228.1	227.3
Provision (reversal of provision) for possible losses	0.2	(1.1)	(3.2)
Asset impairment charges	6.8	8.2	10.0
Deferred income taxes	30.9	11.0	24.0
Share of affiliates' earnings, net of dividends	(11.4)	(1.5)	7.0
Change in income taxes payable	9.1	(7.3)	(8.8)
Change in accrued operating lease expense	(7.6)	(13.1)	(7.4)
Employee benefit plans	(5.3)	(21.6)	(50.0)
Other	4.9	3.7	8.0
Net cash provided by operating activities	306.8	243.7	267.0
Investing Activities
Additions to operating assets and facilities	(466.4)	(520.2)	(398.6)
Loans extended	(31.9)
Investments in affiliates	(116.2)	(64.7)	(81.4)
Other	(0.1)	(0.2)	(0.4)
Portfolio investments and capital additions	(614.6)	(585.1)	(480.4)
Purchases of leased-in assets	(61.1)	(5.3)	(10.7)
Portfolio proceeds	154.1	84.3	67.9
Proceeds from sales of other assets	42.2	30.4	25.4
Proceeds from sale-leaseback		79.0	45.7
Net (decrease) increase in restricted cash	21.4	(23.4)	7.9
Other		2.4	36.0
Net cash used in investing activities	(458.0)	(417.7)	(308.2)
Financing Activities
Net proceeds from issuances of debt (original maturities longer than 90 days)	790.3	573.8	636.1
Repayments of debt (original maturities longer than 90 days)	(312.8)	(344.2)	(480.8)
Net (decrease) increase in debt with original maturities of 90 days or less	(85.0)	46.8	(55.3)
Payments on capital lease obligations	(18.5)	(12.8)	(9.9)
Stock repurchases			(55.1)
Employee exercises of stock options	6.6	2.5
Dividends	(56.0)	(53.5)	(53.6)
Derivative settlements	(1.4)	(1.6)	(0.9)
Net cash provided by (used in) financing activities	323.2	211.0	(19.5)
Effect of Exchange Rate Changes on Cash and Cash Equivalents	(2.1)	(0.2)	0.2
Net increase (decrease) in Cash and Cash Equivalents during the period	169.9	36.8	(60.5)
Cash and Cash Equivalents at beginning of period	78.5	41.7	102.2
Cash and Cash Equivalents at end of period	$ 248.4	$ 78.5	$ 41.7