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Effective Income Tax Rate Reconciliation, Share-based Compensation, Excess Tax Benefit, Amount

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Reimbursed Management Contract Expense

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Percentage of voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

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Cost associated with reimbursable income. This occurs when a services entity incurs expenses on behalf of the client and passes through the cost of reimbursable expenses to a client.

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Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption.

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This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee.

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Repayment received or receivable for expenses incurred on behalf of a client or customer, other than those reimbursements received by landlords from tenants.

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Amount of cash and cash equivalents restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

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Significant Accounting Policies and Practices - Narrative (Details) $ in Millions	1 Months Ended	3 Months Ended				6 Months Ended	9 Months Ended
	Oct. 31, 2014	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($)	Sep. 30, 2017 USD ($) voting_interest_model_entity variable_interest_entity partnership	Sep. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)	Mar. 31, 2016 USD ($)
Restricted Cash and Investments [Abstract]
Restricted cash and cash equivalents		$ 0.4					$ 0.4		$ 0.3
Financial Instruments
Book overdrafts		26.5					$ 26.5		$ 36.5
Equity Investments in Unconsolidated Entities
Number of ownership interest entities \| partnership							32
Equity earnings in related investments		8.5					$ 8.5
Income from equity method investments		0.6		$ 0.7			10.6	$ 1.8
Ownership percentage	30.00%
Recently Issued Accounting Policies [Abstract]
Reimbursed management contract revenue		165.1	$ 11.9	177.0	$ 35.2	$ 24.4	512.7	501.8
Reimbursed management contract expense							11.9	35.2
Reimbursed management contract expense		165.1		$ 177.0		$ 24.4	512.7	$ 501.8
Recognized excess tax benefit		$ 0.1					$ 0.7
Minimum
Equity Investments in Unconsolidated Entities
Voting interest ownership percentage		30.00%					30.00%
Maximum
Equity Investments in Unconsolidated Entities
Voting interest ownership percentage		50.00%					50.00%
Primary Beneficiary
Equity Investments in Unconsolidated Entities
Number of ownership interest entities \| variable_interest_entity							24
Not Primary Beneficiary
Equity Investments in Unconsolidated Entities
Number of ownership interest entities \| voting_interest_model_entity							8
Additional Paid-in Capital \| Accounting Standards Update 2016-09, Forfeiture Rate Component \| New Accounting Pronouncement, Early Adoption, Effect
Recently Issued Accounting Policies [Abstract]
Recognition of cumulative forfeitures as a result of new accounting pronouncements										$ 0.3