Supplemental Guarantor Information -Condensed Consolidating Balance Sheets (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2015
Supplemental Guarantor Information [Line Items]
Cash and cash equivalents	$ 251.7	$ 263.7	$ 248.2	$ 37.6
Accounts receivable, net of allowance for doubtful accounts	1,985.8	2,168.6
Merchandise inventory	493.4	452.0
Miscellaneous receivables	239.4	234.9
Prepaid expenses and other	127.3	118.9
Total current assets	3,097.6	3,238.1
Property and equipment, net	162.4	163.7
Goodwill	2,459.1	2,455.0
Other intangible assets, net	1,015.1	1,055.6
Deferred financing costs, net	22.6	33.4
Other assets	40.5	36.0
Investment from and advances to subsidiaries	0.0	0.0
Total assets	6,774.7	6,948.4
Accounts payable-trade	1,064.3	1,072.9
Accounts payable-inventory financing	445.0	580.4
Current maturities of long-term debt	18.5	18.5
Deferred revenue	205.1	172.6
Accrued Expenses	489.9	436.3
Total current liabilities	2,222.8	2,280.7
Long-term Debt, Excluding Current Maturities	3,262.0	3,215.9
Deferred income taxes	350.4	369.2
Other liabilities	32.2	37.1
Total long-term liabilities	3,644.6	3,622.2
Total stockholders' equity	907.3	1,045.5
Total liabilities and stockholders' equity	6,774.7	6,948.4
Consolidating Adjustments [Member]
Supplemental Guarantor Information [Line Items]
Cash and cash equivalents	(23.6)	0.0	(19.8)	(39.4)
Accounts receivable, net of allowance for doubtful accounts	0.0	0.0
Merchandise inventory	0.0	0.0
Miscellaneous receivables	0.0	0.0
Prepaid expenses and other	0.0	0.0
Total current assets	(23.6)	0.0
Property and equipment, net	0.0	0.0
Goodwill	0.0	0.0
Other intangible assets, net	0.0	0.0
Other assets	(237.8)	(236.3)
Investment from and advances to subsidiaries	(3,878.7)	(4,068.8)
Total assets	(4,140.1)	(4,305.1)
Accounts payable-trade	(23.6)	0.0
Accounts payable-inventory financing	0.0	0.0
Current maturities of long-term debt	0.0	0.0
Deferred revenue	0.0	0.0
Accrued Expenses	0.5	(0.1)
Total current liabilities	(23.1)	(0.1)
Long-term Debt, Excluding Current Maturities	0.0	0.0
Deferred income taxes	(3.1)	(3.2)
Other liabilities	(235.2)	(233.0)
Total long-term liabilities	(238.3)	(236.2)
Total stockholders' equity	(3,878.7)	(4,068.8)
Total liabilities and stockholders' equity	(4,140.1)	(4,305.1)
Parent Guarantor [Member]
Supplemental Guarantor Information [Line Items]
Cash and cash equivalents	0.0		0.0	0.0
Total current liabilities	0.0
Total long-term liabilities	0.0	0.0
Total stockholders' equity	925.6	1,045.5
Total liabilities and stockholders' equity	925.6	1,045.5
Parent Guarantor [Member] | Reportable Legal Entities [Member]
Supplemental Guarantor Information [Line Items]
Cash and cash equivalents	0.0	0.0
Accounts receivable, net of allowance for doubtful accounts	0.0	0.0
Merchandise inventory	0.0	0.0
Miscellaneous receivables	0.0	0.0
Prepaid expenses and other	0.0	0.0
Total current assets	0.0	0.0
Property and equipment, net	0.0	0.0
Goodwill	0.0	0.0
Other intangible assets, net	0.0	0.0
Other assets	3.1	3.2
Investment from and advances to subsidiaries	922.5	1,042.3
Total assets	925.6	1,045.5
Accounts payable-trade	0.0	0.0
Accounts payable-inventory financing	0.0	0.0
Current maturities of long-term debt	0.0	0.0
Deferred revenue	0.0	0.0
Accrued Expenses	0.0	0.0
Total current liabilities		0.0
Long-term Debt, Excluding Current Maturities	0.0	0.0
Deferred income taxes	0.0	0.0
Other liabilities	0.0	0.0
Subsidiary Issuer [Member]
Supplemental Guarantor Information [Line Items]
Cash and cash equivalents	204.9		185.4	45.1
Total current liabilities	247.9	215.9
Total long-term liabilities	3,303.6	3,266.2
Total stockholders' equity	893.9	1,042.3
Total liabilities and stockholders' equity	4,445.4	4,524.4
Subsidiary Issuer [Member] | Reportable Legal Entities [Member]
Supplemental Guarantor Information [Line Items]
Cash and cash equivalents	204.9	222.7
Accounts receivable, net of allowance for doubtful accounts	0.0	0.0
Merchandise inventory	0.0	0.0
Miscellaneous receivables	89.0	92.6
Prepaid expenses and other	17.0	14.3
Total current assets	310.9	329.6
Property and equipment, net	103.4	105.6
Goodwill	751.8	751.8
Other intangible assets, net	288.9	291.5
Other assets	26.3	19.4
Investment from and advances to subsidiaries	2,964.1	3,026.5
Total assets	4,445.4	4,524.4
Accounts payable-trade	29.5	25.9
Accounts payable-inventory financing	0.4	1.2
Current maturities of long-term debt	14.9	14.9
Deferred revenue	0.0	0.0
Accrued Expenses	203.1	173.9
Long-term Debt, Excluding Current Maturities	3,181.2	3,136.3
Deferred income taxes	95.8	99.1
Other liabilities	26.6	30.8
Guarantor Subsidiaries [Member]
Supplemental Guarantor Information [Line Items]
Total current liabilities	1,633.0	1,774.0
Total long-term liabilities	208.3	221.1
Total stockholders' equity	2,729.3	2,804.2
Total liabilities and stockholders' equity	4,570.6	4,799.3
Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Supplemental Guarantor Information [Line Items]
Cash and cash equivalents	0.0	3.1	0.0	0.0
Accounts receivable, net of allowance for doubtful accounts	1,680.8	1,904.9
Merchandise inventory	416.7	390.6
Miscellaneous receivables	136.7	130.1
Prepaid expenses and other	79.1	69.0
Total current assets	2,313.3	2,497.7
Property and equipment, net	48.6	49.3
Goodwill	1,439.0	1,439.0
Other intangible assets, net	529.9	565.1
Other assets	247.4	248.2
Investment from and advances to subsidiaries	(7.6)	0.0
Total assets	4,570.6	4,799.3
Accounts payable-trade	875.4	895.3
Accounts payable-inventory financing	427.3	559.5
Current maturities of long-term debt	3.6	3.6
Deferred revenue	104.4	100.8
Accrued Expenses	222.3	214.8
Long-term Debt, Excluding Current Maturities	12.2	12.1
Deferred income taxes	190.5	205.4
Other liabilities	5.6	3.6
Non-Guarantor Subsidiaries [Member]
Supplemental Guarantor Information [Line Items]
Cash and cash equivalents	70.4		82.6	31.9
Total current assets		410.8
Total current liabilities	365.0	290.9
Total long-term liabilities	371.0	371.1
Total stockholders' equity	237.2	222.3
Total liabilities and stockholders' equity	973.2	884.3
Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Supplemental Guarantor Information [Line Items]
Cash and cash equivalents	70.4	37.9
Accounts receivable, net of allowance for doubtful accounts	305.0	263.7
Merchandise inventory	76.7	61.4
Miscellaneous receivables	13.7	12.2
Prepaid expenses and other	31.2	35.6
Total current assets	497.0
Property and equipment, net	10.4	8.8
Goodwill	268.3	264.2
Other intangible assets, net	196.3	199.0
Other assets	1.5	1.5
Investment from and advances to subsidiaries	(0.3)	0.0
Total assets	973.2	884.3
Accounts payable-trade	183.0	151.7
Accounts payable-inventory financing	17.3	19.7
Current maturities of long-term debt	0.0	0.0
Deferred revenue	100.7	71.8
Accrued Expenses	64.0	47.7
Long-term Debt, Excluding Current Maturities	68.6	67.5
Deferred income taxes	67.2	67.9
Other liabilities	235.2	235.7
Co-Issuer [Member]
Supplemental Guarantor Information [Line Items]
Cash and cash equivalents	0.0		$ 0.0	$ 0.0
Total current liabilities	0.0	0.0
Total long-term liabilities	0.0	0.0
Total stockholders' equity	0.0	0.0
Total liabilities and stockholders' equity	0.0	0.0
Co-Issuer [Member] | Reportable Legal Entities [Member]
Supplemental Guarantor Information [Line Items]
Cash and cash equivalents	0.0	0.0
Accounts receivable, net of allowance for doubtful accounts	0.0	0.0
Merchandise inventory	0.0	0.0
Miscellaneous receivables	0.0	0.0
Prepaid expenses and other	0.0	0.0
Total current assets	0.0	0.0
Property and equipment, net	0.0	0.0
Goodwill	0.0	0.0
Other intangible assets, net	0.0	0.0
Other assets	0.0	0.0
Investment from and advances to subsidiaries	0.0	0.0
Total assets	0.0	0.0
Accounts payable-trade	0.0	0.0
Accounts payable-inventory financing	0.0	0.0
Current maturities of long-term debt	0.0	0.0
Deferred revenue	0.0	0.0
Accrued Expenses	0.0	0.0
Long-term Debt, Excluding Current Maturities	0.0	0.0
Deferred income taxes	0.0	0.0
Other liabilities	$ 0.0	$ 0.0