Supplemental Guarantor Information - Condensed Consolidating Statements of Cash Flows (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Supplemental Guarantor Information [Line Items]
Net cash provided by operating activities	$ 682.3	$ 602.3
Cash flows used in investing activities:
Capital expenditures	(75.0)	(53.4)
Acquisition of business, net of cash acquired	(75.0)	0.0
Net cash used in investing activities	(150.0)	(53.4)
Cash flows used in financing activities:
Proceeds from borrowings under revolving credit facility	1,860.5	688.9
Repayments of borrowings under revolving credit facility	(1,834.5)	(681.9)
Repayments of long-term debt	(19.7)	(18.2)
Proceeds from Issuance of Long-term Debt	600.0	0.0
Payments to extinguish long-term debt	(538.1)	0.0
Net change in accounts payable-inventory financing	(17.4)	(90.1)
Repurchases of common stock	(493.3)	(232.5)
Payment of incentive compensation plan withholding taxes	(21.3)	(27.1)
Dividend payments	(128.9)	(95.5)
Capital contributions	0.0	0.0
Other	24.2	21.1
Distributions and advances from (to) affiliates	0.0	0.0
Net cash used in financing activities	(568.5)	(435.3)
Effect of exchange rate changes on cash and cash equivalents	(2.7)	(2.7)
Net (decrease) increase in cash and cash equivalents	(38.9)	110.9
Cash and cash equivalents—beginning of period	205.8	144.2
Cash and cash equivalents—end of period	166.9	255.1
Consolidating Adjustments
Supplemental Guarantor Information [Line Items]
Net cash provided by operating activities	(27.4)	(7.4)
Cash flows used in investing activities:
Capital expenditures	0.0	0.0
Acquisition of business, net of cash acquired	0.0
Net cash used in investing activities	0.0	0.0
Cash flows used in financing activities:
Proceeds from borrowings under revolving credit facility	0.0	0.0
Repayments of borrowings under revolving credit facility	0.0	0.0
Repayments of long-term debt	0.0	0.0
Proceeds from Issuance of Long-term Debt	0.0
Payments to extinguish long-term debt	0.0
Net change in accounts payable-inventory financing	0.0	0.0
Repurchases of common stock	0.0	0.0
Payment of incentive compensation plan withholding taxes	0.0	0.0
Dividend payments	0.0	0.0
Capital contributions	0.0	0.0
Other	0.0	0.0
Distributions and advances from (to) affiliates	8.6	(6.0)
Net cash used in financing activities	8.6	(6.0)
Effect of exchange rate changes on cash and cash equivalents	0.0	0.0
Net (decrease) increase in cash and cash equivalents	(18.8)	(13.4)
Cash and cash equivalents—beginning of period	(16.9)	(1.9)
Cash and cash equivalents—end of period	(35.7)	(15.3)
Reportable Legal Entities
Cash flows used in financing activities:
Proceeds from Issuance of Long-term Debt	0.0
Payments to extinguish long-term debt	0.0
Parent Guarantor
Cash flows used in investing activities:
Acquisition of business, net of cash acquired	0.0
Parent Guarantor | Reportable Legal Entities
Supplemental Guarantor Information [Line Items]
Net cash provided by operating activities	0.0	0.0
Cash flows used in investing activities:
Capital expenditures	0.0	0.0
Net cash used in investing activities	0.0	0.0
Cash flows used in financing activities:
Proceeds from borrowings under revolving credit facility	0.0	0.0
Repayments of borrowings under revolving credit facility	0.0	0.0
Repayments of long-term debt	0.0	0.0
Proceeds from Issuance of Long-term Debt	0.0
Payments to extinguish long-term debt	0.0
Net change in accounts payable-inventory financing	0.0	0.0
Repurchases of common stock	(493.3)	(232.5)
Payment of incentive compensation plan withholding taxes	(21.3)	(27.1)
Dividend payments	(128.9)	(95.5)
Capital contributions	0.0	0.0
Other	0.0	0.0
Distributions and advances from (to) affiliates	643.5	355.1
Net cash used in financing activities	0.0	0.0
Effect of exchange rate changes on cash and cash equivalents	0.0	0.0
Net (decrease) increase in 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
Subsidiary Issuer
Cash flows used in investing activities:
Acquisition of business, net of cash acquired	0.0
Subsidiary Issuer | Reportable Legal Entities
Supplemental Guarantor Information [Line Items]
Net cash provided by operating activities	(6.3)	(78.9)
Cash flows used in investing activities:
Capital expenditures	(46.4)	(40.9)
Net cash used in investing activities	(46.4)	(40.9)
Cash flows used in financing activities:
Proceeds from borrowings under revolving credit facility	1,860.5	640.0
Repayments of borrowings under revolving credit facility	(1,834.5)	(640.0)
Repayments of long-term debt	(11.0)	(11.2)
Proceeds from Issuance of Long-term Debt	600.0
Payments to extinguish long-term debt	(538.1)
Net change in accounts payable-inventory financing	0.0	(0.8)
Repurchases of common stock	0.0	0.0
Payment of incentive compensation plan withholding taxes	0.0	0.0
Dividend payments	0.0	0.0
Capital contributions	(76.0)	0.0
Other	28.8	25.8
Distributions and advances from (to) affiliates	(28.9)	213.2
Net cash used in financing activities	0.8	227.0
Effect of exchange rate changes on cash and cash equivalents	0.0	0.0
Net (decrease) increase in cash and cash equivalents	(51.9)	107.2
Cash and cash equivalents—beginning of period	176.0	113.7
Cash and cash equivalents—end of period	124.1	220.9
Guarantor Subsidiaries
Cash flows used in investing activities:
Acquisition of business, net of cash acquired	0.0
Guarantor Subsidiaries | Reportable Legal Entities
Supplemental Guarantor Information [Line Items]
Net cash provided by operating activities	620.6	608.4
Cash flows used in investing activities:
Capital expenditures	(19.5)	(3.5)
Net cash used in investing activities	(19.5)	(3.5)
Cash flows used in financing activities:
Proceeds from borrowings under revolving credit facility	0.0	0.0
Repayments of borrowings under revolving credit facility	0.0	0.0
Repayments of long-term debt	0.0	0.0
Proceeds from Issuance of Long-term Debt	0.0
Payments to extinguish long-term debt	0.0
Net change in accounts payable-inventory financing	(24.2)	(85.8)
Repurchases of common stock	0.0	0.0
Payment of incentive compensation plan withholding taxes	0.0	0.0
Dividend payments	0.0	0.0
Capital contributions	0.0	47.5
Other	(4.4)	(4.3)
Distributions and advances from (to) affiliates	(572.5)	(562.3)
Net cash used in financing activities	(601.1)	(604.9)
Effect of exchange rate changes on cash and cash equivalents	0.0	0.0
Net (decrease) increase in 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
Non-Guarantor Subsidiaries
Cash flows used in investing activities:
Acquisition of business, net of cash acquired	(75.0)
Non-Guarantor Subsidiaries | Reportable Legal Entities
Supplemental Guarantor Information [Line Items]
Net cash provided by operating activities	95.4	80.2
Cash flows used in investing activities:
Capital expenditures	(9.1)	(9.0)
Net cash used in investing activities	(84.1)	(9.0)
Cash flows used in financing activities:
Proceeds from borrowings under revolving credit facility	0.0	48.9
Repayments of borrowings under revolving credit facility	0.0	(41.9)
Repayments of long-term debt	(8.7)	(7.0)
Proceeds from Issuance of Long-term Debt	0.0
Payments to extinguish long-term debt	0.0
Net change in accounts payable-inventory financing	6.8	(3.5)
Repurchases of common stock	0.0	0.0
Payment of incentive compensation plan withholding taxes	0.0	0.0
Dividend payments	0.0	0.0
Capital contributions	76.0	(47.5)
Other	(0.2)	(0.4)
Distributions and advances from (to) affiliates	(50.7)	0.0
Net cash used in financing activities	23.2	(51.4)
Effect of exchange rate changes on cash and cash equivalents	(2.7)	(2.7)
Net (decrease) increase in cash and cash equivalents	31.8	17.1
Cash and cash equivalents—beginning of period	46.7	32.4
Cash and cash equivalents—end of period	78.5	49.5
Affiliated Entity
Cash flows used in investing activities:
Acquisition of business, net of cash acquired	0.0
Affiliated Entity | Reportable Legal Entities
Supplemental Guarantor Information [Line Items]
Net cash provided by operating activities	0.0	0.0
Cash flows used in investing activities:
Capital expenditures	0.0	0.0
Net cash used in investing activities	0.0	0.0
Cash flows used in financing activities:
Proceeds from borrowings under revolving credit facility	0.0	0.0
Repayments of borrowings under revolving credit facility	0.0	0.0
Repayments of long-term debt	0.0	0.0
Net change in accounts payable-inventory financing	0.0	0.0
Repurchases of common stock	0.0	0.0
Payment of incentive compensation plan withholding taxes	0.0	0.0
Dividend payments	0.0	0.0
Capital contributions	0.0	0.0
Other	0.0	0.0
Distributions and advances from (to) affiliates	0.0	0.0
Net cash used in financing activities	0.0	0.0
Effect of exchange rate changes on cash and cash equivalents	0.0	0.0
Net (decrease) increase in 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