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Self-Insurance (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Insurance [Line Items]
Self-insurance reserves - current portion	$ 566.8	$ 529.2
Self-insurance reserves - long-term portion	217.9	207.6
Self-insurance reserves [Member]
Insurance [Line Items]
Self-insurance reserves - current portion	27.2	27.2
Self-insurance reserves - long-term portion	48.7	47.6
Total self-insurance liabilities	$ 75.9	$ 74.8

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
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