Condensed Consolidating Financial Statements (Statements of Cash Flows) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Condensed Cash Flow Statements, Captions [Line Items]
Cash flows from operating activities:	$ 396.1	$ 495.5	$ 325.1
Cash flows from investing activities:
Proceeds from the disposal of property, plant and equipment	1.3	0.1	0.2
Purchases of property, plant and equipment	(105.6)	(95.2)	(98.3)
Purchases of short-term investments	(2.9)	0.0	0.0
Net proceeds from sale of businesses	43.5	114.7	0.0
Insurance recoveries received for property damage incurred from natural disaster	79.6	10.9	0.0
Net cash used in investing activities	15.9	30.5	(98.1)
Cash flows from financing activities:
Short-term debt payments	(5.3)	40.3	(31.9)
Short-term debt proceeds	5.3	40.3	30.4
Asset securitization borrowings	184.5	155.0	315.0
Asset securitization payments	(167.5)	(163.0)	(89.0)
Long-term debt payments	(6.4)	(3.0)	(200.9)
Borrowings from credit facility	2,367.0	2,435.9	2,376.5
Payments on credit facility	(2,269.5)	(2,395.0)	(2,265.5)
Payments of deferred financing costs	(0.3)	0.0	(0.2)
Proceeds from employee stock purchases	3.3	3.3	3.1
Repurchases of common stock to satisfy employee withholding tax obligations	(24.0)	(26.9)	(26.1)
Repurchases of common stock	(400.0)	(450.2)	(250.0)
Intercompany debt	0.0	0.0	0.0
Increase (Decrease) in Accounts Payable, Related Parties	0.0	0.0	0.0
Cash dividends paid	(110.5)	(93.9)	(79.7)
Net cash used in financing activities	(423.4)	(537.8)	(218.3)
Cash and Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect	(11.4)	(11.8)	8.7
Cash and cash equivalents, beginning of year	46.3	68.2	50.2
Cash and cash equivalents, end of year	37.3	46.3	68.2
Effect of Exchange Rate on Cash and Cash Equivalents	2.4	(10.1)	9.3
Parent [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash flows from operating activities:	(30.2)	53.7	467.4
Cash flows from investing activities:
Proceeds from the disposal of property, plant and equipment	0.0	0.0	0.0
Purchases of property, plant and equipment	0.0	0.0	0.0
Purchases of short-term investments	0.0
Net proceeds from sale of businesses	0.0	0.0
Insurance recoveries received for property damage incurred from natural disaster	0.0	0.0
Net cash used in investing activities	0.0	0.0	0.0
Cash flows from financing activities:
Short-term debt payments	0.0	0.0	0.0
Short-term debt proceeds	0.0	0.0	0.0
Asset securitization borrowings	0.0	0.0	0.0
Asset securitization payments	0.0	0.0	0.0
Long-term debt payments	0.0	0.0	(200.0)
Borrowings from credit facility	2,367.0	2,435.9	2,376.5
Payments on credit facility	(2,269.5)	(2,395.0)	(2,265.5)
Payments of deferred financing costs	0.0		0.0
Proceeds from employee stock purchases	3.3	3.3	3.1
Repurchases of common stock to satisfy employee withholding tax obligations	(24.0)	(26.9)	(26.1)
Repurchases of common stock	(400.0)	(450.2)	(250.0)
Intercompany debt	21.8	(14.5)	56.4
Increase (Decrease) in Accounts Payable, Related Parties	441.5	487.8	(81.7)
Cash dividends paid	(110.5)	(93.9)	(79.7)
Net cash used in financing activities	29.6	(53.5)	(467.0)
Cash and Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect	(0.6)	0.2	0.4
Cash and cash equivalents, beginning of year	1.8	1.6	1.2
Cash and cash equivalents, end of year	1.2	1.8	1.6
Effect of Exchange Rate on Cash and Cash Equivalents	0.0	0.0	0.0
Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash flows from operating activities:	421.8	477.9	31.1
Cash flows from investing activities:
Proceeds from the disposal of property, plant and equipment	1.0	0.0	0.1
Purchases of property, plant and equipment	(95.2)	(76.0)	(70.7)
Purchases of short-term investments	0.0
Net proceeds from sale of businesses	42.8	2.7
Insurance recoveries received for property damage incurred from natural disaster	79.6	10.9
Net cash used in investing activities	28.2	(62.4)	(70.6)
Cash flows from financing activities:
Short-term debt payments	0.0	0.0	0.0
Short-term debt proceeds	0.0	0.0	0.0
Asset securitization borrowings	0.0	0.0	0.0
Asset securitization payments	0.0	0.0	0.0
Long-term debt payments	(3.7)	(2.9)	(0.3)
Borrowings from credit facility	0.0	0.0	0.0
Payments on credit facility	0.0	0.0	0.0
Payments of deferred financing costs	0.0		0.0
Proceeds from employee stock purchases	0.0	0.0	0.0
Repurchases of common stock to satisfy employee withholding tax obligations	0.0	0.0	0.0
Repurchases of common stock	0.0	0.0	0.0
Intercompany debt	(15.1)	83.3	(34.9)
Increase (Decrease) in Accounts Payable, Related Parties	(429.6)	(508.5)	85.6
Cash dividends paid	0.0	0.0	0.0
Net cash used in financing activities	(448.4)	(428.1)	50.4
Cash and Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect	1.6	(12.6)	10.9
Cash and cash equivalents, beginning of year	15.4	28.0	17.1
Cash and cash equivalents, end of year	17.5	15.4	28.0
Effect of Exchange Rate on Cash and Cash Equivalents	0.5	0.0	0.0
Non-Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash flows from operating activities:	4.5	(36.1)	(173.4)
Cash flows from investing activities:
Proceeds from the disposal of property, plant and equipment	0.3	0.1	0.1
Purchases of property, plant and equipment	(10.4)	(19.2)	(27.6)
Purchases of short-term investments	(2.9)
Net proceeds from sale of businesses	0.7	112.0
Insurance recoveries received for property damage incurred from natural disaster	0.0	0.0
Net cash used in investing activities	(12.3)	92.9	(27.5)
Cash flows from financing activities:
Short-term debt payments	(5.3)	40.3	(31.9)
Short-term debt proceeds	5.3	40.3	30.4
Asset securitization borrowings	184.5	155.0	315.0
Asset securitization payments	(167.5)	(163.0)	(89.0)
Long-term debt payments	(2.7)	(0.1)	(0.6)
Borrowings from credit facility	0.0	0.0	0.0
Payments on credit facility	0.0	0.0	0.0
Payments of deferred financing costs	(0.3)		(0.2)
Proceeds from employee stock purchases	0.0	0.0	0.0
Repurchases of common stock to satisfy employee withholding tax obligations	0.0	0.0	0.0
Repurchases of common stock	0.0	0.0	0.0
Intercompany debt	(6.7)	(68.8)	(21.5)
Increase (Decrease) in Accounts Payable, Related Parties	(11.9)	20.7	(3.9)
Cash dividends paid	0.0	0.0	0.0
Net cash used in financing activities	(4.6)	(56.2)	198.3
Cash and Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect	(12.4)	0.6	(2.6)
Cash and cash equivalents, beginning of year	29.1	38.6	31.9
Cash and cash equivalents, end of year	18.6	29.1	38.6
Effect of Exchange Rate on Cash and Cash Equivalents	1.9	(10.1)	9.3
Eliminations [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash flows from operating activities:	0.0	0.0	0.0
Cash flows from investing activities:
Proceeds from the disposal of property, plant and equipment	0.0	0.0	0.0
Purchases of property, plant and equipment	0.0	0.0	0.0
Net proceeds from sale of businesses	0.0	0.0
Insurance recoveries received for property damage incurred from natural disaster	0.0	0.0
Net cash used in investing activities	0.0	0.0	0.0
Cash flows from financing activities:
Short-term debt payments	0.0	0.0	0.0
Short-term debt proceeds	0.0	0.0	0.0
Asset securitization borrowings	0.0	0.0	0.0
Asset securitization payments	0.0	0.0	0.0
Long-term debt payments	0.0	0.0	0.0
Borrowings from credit facility	0.0	0.0	0.0
Payments on credit facility	0.0	0.0	0.0
Payments of deferred financing costs	0.0		0.0
Proceeds from employee stock purchases	0.0	0.0	0.0
Repurchases of common stock to satisfy employee withholding tax obligations	0.0	0.0	0.0
Repurchases of common stock	0.0	0.0	0.0
Intercompany debt	0.0	0.0	0.0
Increase (Decrease) in Accounts Payable, Related Parties	0.0	0.0	0.0
Cash dividends paid	0.0	0.0	0.0
Net cash used in financing activities	0.0	0.0	0.0
Cash and Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect	0.0	0.0	0.0
Cash and cash equivalents, beginning of year	0.0	0.0	0.0
Cash and cash equivalents, end of year	0.0	0.0	0.0
Effect of Exchange Rate on Cash and Cash Equivalents	$ 0.0	$ 0.0	$ 0.0