Financial Information for Guarantor Subsidiaries and Non-Guarantor Subsidiaries - Supplemental Condensed Consolidating Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Assets
Cash and cash equivalents	$ 168.2	$ 788.8
Restricted cash	38.7	29.0
Accounts receivable, net	599.2	540.9
Notes receivable, net	113.9	143.5
Inventories	215.6	243.1
Prepaid expenses, deposits and other current assets	232.7	131.1
Property and equipment, net	547.0	568.2
Investment in subsidiaries	0.0	0.0
Goodwill	3,279.9	2,956.1	$ 2,888.4
Intangible assets, net	1,809.1	1,604.6
Intercompany balances	0.0	0.0
Software, net	285.3	339.4
Other assets	428.2	380.6
Total assets	7,717.8	7,725.3	7,087.4
Liabilities and stockholders’ (deficit) equity
Current portion of long-term debt	45.0	40.3
Other current liabilities	702.3	699.5
Long-term debt, excluding current portion	8,991.9	8,736.3
Other long-term liabilities	441.8	276.2
Intercompany balances	0.0	0.0
Stockholders’ (deficit) equity	(2,463.2)	(2,027.0)	$ (1,935.7)
Total liabilities and stockholders’ deficit	7,717.8	7,725.3
Non-current restricted cash	13.1	16.3
Reportable Legal Entities | Parent Company
Assets
Cash and cash equivalents	73.5	732.6
Restricted cash	0.0	0.0
Accounts receivable, net	0.0	0.4
Notes receivable, net	0.0	0.0
Inventories	0.0	0.0
Prepaid expenses, deposits and other current assets	6.2	6.5
Property and equipment, net	31.0	28.8
Investment in subsidiaries	2,835.9	3,098.7
Goodwill	0.0	0.0
Intangible assets, net	42.6	15.7
Intercompany balances	0.0	0.0
Software, net	58.6	67.2
Other assets	110.0	234.4
Total assets	3,157.8	4,184.3
Liabilities and stockholders’ (deficit) equity
Current portion of long-term debt	0.0	0.0
Other current liabilities	63.8	67.6
Long-term debt, excluding current portion	0.0	0.0
Other long-term liabilities	105.8	68.8
Intercompany balances	5,451.4	6,074.9
Stockholders’ (deficit) equity	(2,463.2)	(2,027.0)
Total liabilities and stockholders’ deficit	3,157.8	4,184.3
Reportable Legal Entities | Guarantor Subsidiaries
Assets
Cash and cash equivalents	0.0	0.0
Restricted cash	31.6	28.3
Accounts receivable, net	204.8	192.6
Notes receivable, net	100.6	121.1
Inventories	81.7	91.8
Prepaid expenses, deposits and other current assets	92.5	41.6
Property and equipment, net	218.6	295.6
Investment in subsidiaries	1,093.4	987.7
Goodwill	1,896.8	1,880.4
Intangible assets, net	1,291.4	1,335.3
Intercompany balances	0.0	0.0
Software, net	128.3	199.0
Other assets	45.9	62.0
Total assets	5,185.6	5,235.4
Liabilities and stockholders’ (deficit) equity
Current portion of long-term debt	0.0	0.0
Other current liabilities	247.9	254.2
Long-term debt, excluding current portion	0.0	0.0
Other long-term liabilities	637.3	650.3
Intercompany balances	48.1	37.4
Stockholders’ (deficit) equity	4,252.3	4,293.5
Total liabilities and stockholders’ deficit	5,185.6	5,235.4
Non-current restricted cash	12.2	15.6
Reportable Legal Entities | Non-Guarantor Subsidiaries
Assets
Cash and cash equivalents	95.1	59.4
Restricted cash	6.3	0.1
Accounts receivable, net	315.2	279.8
Notes receivable, net	13.3	22.4
Inventories	110.8	131.8
Prepaid expenses, deposits and other current assets	70.5	52.7
Property and equipment, net	218.2	179.9
Investment in subsidiaries	0.0	0.0
Goodwill	1,142.9	835.4
Intangible assets, net	441.0	218.7
Intercompany balances	0.0	222.5
Software, net	60.2	48.5
Other assets	307.8	270.3
Total assets	2,781.3	2,321.5
Liabilities and stockholders’ (deficit) equity
Current portion of long-term debt	3.3	7.5
Other current liabilities	254.1	206.4
Long-term debt, excluding current portion	0.8	3.3
Other long-term liabilities	171.9	110.9
Intercompany balances	554.4	0.0
Stockholders’ (deficit) equity	1,796.8	1,993.4
Total liabilities and stockholders’ deficit	2,781.3	2,321.5
Non-current restricted cash	0.9	0.7
Reportable Legal Entities | SGI
Assets
Cash and cash equivalents	0.9	0.0
Restricted cash	0.8	0.6
Accounts receivable, net	79.2	68.1
Notes receivable, net	0.0	0.0
Inventories	40.4	40.7
Prepaid expenses, deposits and other current assets	63.3	30.3
Property and equipment, net	112.1	91.5
Investment in subsidiaries	974.5	867.9
Goodwill	240.2	240.3
Intangible assets, net	34.1	34.9
Intercompany balances	6,053.9	5,889.8
Software, net	38.2	24.7
Other assets	404.4	388.8
Total assets	8,042.0	7,677.6
Liabilities and stockholders’ (deficit) equity
Current portion of long-term debt	41.7	32.8
Other current liabilities	162.4	199.0
Long-term debt, excluding current portion	8,991.1	8,733.0
Other long-term liabilities	7.6	11.3
Intercompany balances	0.0	0.0
Stockholders’ (deficit) equity	(1,160.8)	(1,298.5)
Total liabilities and stockholders’ deficit	8,042.0	7,677.6
Eliminating Entries
Assets
Cash and cash equivalents	(1.3)	(3.2)
Restricted cash	0.0	0.0
Accounts receivable, net	0.0	0.0
Notes receivable, net	0.0	0.0
Inventories	(17.3)	(21.2)
Prepaid expenses, deposits and other current assets	0.2	0.0
Property and equipment, net	(32.9)	(27.6)
Investment in subsidiaries	(4,903.8)	(4,954.3)
Goodwill	0.0	0.0
Intangible assets, net	0.0	0.0
Intercompany balances	(6,053.9)	(6,112.3)
Software, net	0.0	0.0
Other assets	(439.9)	(574.9)
Total assets	(11,448.9)	(11,693.5)
Liabilities and stockholders’ (deficit) equity
Current portion of long-term debt	0.0	0.0
Other current liabilities	(25.9)	(27.7)
Long-term debt, excluding current portion	0.0	0.0
Other long-term liabilities	(480.8)	(565.1)
Intercompany balances	(6,053.9)	(6,112.3)
Stockholders’ (deficit) equity	(4,888.3)	(4,988.4)
Total liabilities and stockholders’ deficit	$ (11,448.9)	$ (11,693.5)