Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net income	$ 127.0	$ 58.2
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	66.6	64.2
Equity-based compensation expense	8.1	12.1
Deferred income taxes	(13.4)	(19.1)
Amortization of deferred financing fees, debt premium and debt discount, net	1.2	3.2
Net loss on extinguishments of long-term debt	0.0	57.4
Mark-to-market gain on interest rate cap agreements	0.0	(0.5)
Other	(0.1)	2.1
Changes in assets and liabilities:
Accounts receivable	60.5	184.7
Merchandise inventory	(72.4)	(36.0)
Other assets	15.4	(20.0)
Accounts payable-trade	(29.8)	(10.4)
Other current liabilities	59.5	78.7
Long-term liabilities	(0.4)	(4.7)
Net cash provided by operating activities	222.2	369.9
Cash flows used in investing activities:
Capital expenditures	(15.9)	(19.6)
Net cash used in investing activities	(15.9)	(19.6)
Cash flows used in financing activities:
Proceeds from borrowings under revolving credit facilities	170.0	44.1
Repayments of borrowings under revolving credit facilities	(170.0)	(6.1)
Repayments of long-term debt	(3.7)	(3.7)
Proceeds from issuance of long-term debt	0.0	2,083.0
Payments to extinguish long-term debt	0.0	(2,121.3)
Payments of debt financing fees	0.0	(9.6)
Net change in accounts payable-inventory financing	24.9	(135.7)
Premium payments on interest rate cap agreements	(12.6)	0.0
Proceeds from stock option exercises	7.3	4.4
Proceeds from Coworker Stock Purchase Plan	2.4	2.1
Repurchases of common stock	(109.2)	(175.4)
Payment of incentive compensation plan withholding taxes	(8.7)	(18.3)
Dividends	(32.0)	(25.5)
Other	0.4	(0.2)
Net cash used in financing activities	(131.2)	(362.2)
Effect of exchange rate changes on cash and cash equivalents	1.7	(0.1)
Net increase (decrease) in cash and cash equivalents	76.8	(12.0)
Cash and cash equivalents—beginning of period	144.2	263.7
Cash and cash equivalents—end of period	221.0	251.7
Supplementary disclosure of cash flow information:
Interest paid	(42.7)	(48.4)
Taxes paid, net	$ (10.6)	$ (6.3)