Investment in PersolKelly Asia Pacific (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Investment in equity affiliate	$ 120.3	$ 117.4
Accounts payable and accrued liabilities	$ 497.0	537.7
PersolKelly Asia Pacific [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	49.00%
Due from PersolKelly Asia Pacific	$ 2.8
Advances to PersolKelly Asia Pacific	2.9
Due to PersolKelly Asia Pacific		2.3
PersolKelly Asia Pacific [Member]
Schedule of Equity Method Investments [Line Items]
Accounts payable and accrued liabilities	$ 1.6	$ 2.5

Sum of the carrying values as of the balance sheet date of obligations incurred through that date and due within one year (or the operating cycle, if longer), including liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received, taxes, interest, rent and utilities, accrued salaries and bonuses, payroll taxes and fringe benefits.

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