Condensed Consolidating Financial Statements (Statements of Cash Flows) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Condensed Cash Flow Statements, Captions [Line Items]
Cash flows from operating activities	$ 129.0	$ 126.9
Cash flows from investing activities:
Proceeds from the disposal of property, plant and equipment	0.2	0.0
Purchases of property, plant and equipment	(60.5)	(59.4)
Net cash used in investing activities	(60.3)	(59.4)
Cash flows from financing activities:
Short-term borrowings, net	(1.4)	(2.1)
Asset securitization borrowings	275.0	145.0
Asset securitization payments	0.0	(20.0)
Long-term debt payments	(200.8)	(30.9)
Proceeds from Issuance of Long-term Debt	0.0
Borrowings from credit facility	1,883.0	1,715.0
Payments on credit facility	(1,701.0)	(1,493.0)
Proceeds from employee stock purchases	2.3	1.9
Payments of Debt Issuance Costs	0.0	(0.9)
Repurchases of common stock	(250.0)	(300.0)
Repurchases of common stock to satisfy employee withholding tax obligations	(16.0)	(26.3)
Intercompany debt	0.0	0.0
Intercompany financing activity	0.0	0.0
Intercompany investments		0.0
Cash dividends paid	(58.4)	(50.5)
Net cash provided by financing activities	(67.3)	(61.8)
Increase in cash and cash equivalents	1.4	5.7
Effect of exchange rates on cash and cash equivalents	9.1	3.2
Cash and cash equivalents, beginning of period	50.2	38.9
Cash and cash equivalents, end of period	60.7	47.8
Eliminations [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash flows from operating activities	(0.6)	0.0
Cash flows from investing activities:
Proceeds from the disposal of property, plant and equipment	0.1
Purchases of property, plant and equipment	0.0	0.0
Net cash used in investing activities	0.1	0.0
Cash flows from financing activities:
Short-term borrowings, net	0.0	0.0
Asset securitization borrowings	0.0	0.0
Asset securitization payments	0.0	0.0
Long-term debt payments	(0.5)	0.0
Proceeds from Issuance of Long-term Debt	0.0
Borrowings from credit facility	0.4	0.0
Payments on credit facility	0.0	0.0
Proceeds from employee stock purchases	0.0	0.0
Payments of Debt Issuance Costs		0.0
Repurchases of common stock	0.0	0.0
Repurchases of common stock to satisfy employee withholding tax obligations	0.0	0.0
Intercompany debt	0.0	0.0
Intercompany financing activity	0.6	0.0
Intercompany investments		0.0
Cash dividends paid	0.0	0.0
Net cash provided by financing activities	0.5	0.0
Increase in cash and cash equivalents	0.0	0.0
Effect of exchange rates on cash and cash equivalents	0.0	0.0
Cash and cash equivalents, beginning of period	0.0	0.0
Cash and cash equivalents, end of period	0.0	0.0
Parent [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash flows from operating activities	411.6	15.5
Cash flows from investing activities:
Proceeds from the disposal of property, plant and equipment	0.0
Purchases of property, plant and equipment	0.0	0.0
Net cash used in investing activities	0.0	0.0
Cash flows from financing activities:
Short-term borrowings, net	0.0	0.0
Asset securitization borrowings	0.0	0.0
Asset securitization payments	0.0	0.0
Long-term debt payments	(200.0)	(30.0)
Proceeds from Issuance of Long-term Debt	0.0
Borrowings from credit facility	1,883.0	1,715.0
Payments on credit facility	(1,701.0)	(1,493.0)
Proceeds from employee stock purchases	2.3	1.9
Payments of Debt Issuance Costs		(0.9)
Repurchases of common stock	(250.0)	(300.0)
Repurchases of common stock to satisfy employee withholding tax obligations	(16.0)	(26.3)
Intercompany debt	102.8	(6.6)
Intercompany financing activity	(174.3)	178.9
Intercompany investments		0.0
Cash dividends paid	(58.4)	(50.5)
Net cash provided by financing activities	(411.6)	(11.5)
Increase in cash and cash equivalents	0.0	4.0
Effect of exchange rates on cash and cash equivalents	0.0	0.0
Cash and cash equivalents, beginning of period	1.2	0.5
Cash and cash equivalents, end of period	1.2	4.5
Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash flows from operating activities	(2.4)	262.2
Cash flows from investing activities:
Proceeds from the disposal of property, plant and equipment	0.1
Purchases of property, plant and equipment	(48.3)	(52.4)
Net cash used in investing activities	(48.2)	(52.4)
Cash flows from financing activities:
Short-term borrowings, net	0.0	0.0
Asset securitization borrowings	0.0	0.0
Asset securitization payments	0.0	0.0
Long-term debt payments	(0.2)	(0.6)
Proceeds from Issuance of Long-term Debt	(0.1)
Borrowings from credit facility	(0.2)	0.0
Payments on credit facility	0.0	0.0
Proceeds from employee stock purchases	0.0	0.0
Payments of Debt Issuance Costs		0.0
Repurchases of common stock	0.0	0.0
Repurchases of common stock to satisfy employee withholding tax obligations	0.0	0.0
Intercompany debt	(34.8)	(5.1)
Intercompany financing activity	91.0	(196.0)
Intercompany investments		0.0
Cash dividends paid	0.0	0.0
Net cash provided by financing activities	55.9	(201.7)
Increase in cash and cash equivalents	5.3	8.1
Effect of exchange rates on cash and cash equivalents	0.0	0.0
Cash and cash equivalents, beginning of period	17.1	7.8
Cash and cash equivalents, end of period	22.4	15.9
Non-Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash flows from operating activities	(279.6)	(150.8)
Cash flows from investing activities:
Proceeds from the disposal of property, plant and equipment	0.0
Purchases of property, plant and equipment	(12.2)	(7.0)
Net cash used in investing activities	(12.2)	(7.0)
Cash flows from financing activities:
Short-term borrowings, net	(1.4)	(2.1)
Asset securitization borrowings	275.0	145.0
Asset securitization payments	0.0	(20.0)
Long-term debt payments	(0.1)	(0.3)
Proceeds from Issuance of Long-term Debt	0.1
Borrowings from credit facility	(0.2)	0.0
Payments on credit facility	0.0	0.0
Proceeds from employee stock purchases	0.0	0.0
Payments of Debt Issuance Costs		0.0
Repurchases of common stock	0.0	0.0
Repurchases of common stock to satisfy employee withholding tax obligations	0.0	0.0
Intercompany debt	(68.0)	11.7
Intercompany financing activity	82.7	17.1
Intercompany investments		0.0
Cash dividends paid	0.0	0.0
Net cash provided by financing activities	287.9	151.4
Increase in cash and cash equivalents	(3.9)	(6.4)
Effect of exchange rates on cash and cash equivalents	9.1	3.2
Cash and cash equivalents, beginning of period	31.9	30.6
Cash and cash equivalents, end of period	$ 37.1	$ 27.4