Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Statement of Cash Flows [Abstract]
Net income	$ 39.8	$ 18.7
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	17.6	12.3
Deferred financing costs	0.2	0.2
Deferred gain	(0.9)	(1.0)
Stock-based compensation expense	4.0	2.7
Pension expense, net of funding	(3.2)	(2.8)
Changes in fair value of contingent consideration and deferred payment	0.6	0.5
Deferred income taxes	2.0	2.8
Changes in operating assets and liabilities	(22.3)	12.4
Net cash provided by continuing operating activities	37.8	45.8
Net cash used for discontinued operating activities	0.0	(0.3)
Net cash provided by operating activities	37.8	45.5
Investing activities:
Purchases of properties and equipment	(7.0)	(2.7)
Proceeds from (payments for) acquisition-related activity	3.0	(269.2)
Other, net	0.1	0.1
Net cash used for continuing investing activities	(3.9)	(271.8)
Net cash used for discontinued investing activities	0.0	(1.1)
Net cash used for investing activities	(3.9)	(272.9)
Financing activities:
(Decrease) increase in revolving lines of credit, net	(26.6)	223.0
Payments of debt financing fees	0.0	(0.2)
Redemptions of common stock to satisfy withholding taxes related to stock-based compensation	(0.3)	(2.4)
Cash dividends paid to stockholders	(9.0)	(8.4)
Proceeds from stock-based compensation activity	0.9	1.2
Other, net	0.1	(0.2)
Net cash (used for) provided by continuing financing activities	(34.9)	213.0
Net cash used for discontinued financing activities	0.0	0.0
Net cash (used for) provided by financing activities	(34.9)	213.0
Effects of foreign exchange rate changes on cash and cash equivalents	(0.5)	0.7
Decrease in cash and cash equivalents	(1.5)	(13.7)
Cash and cash equivalents at beginning of year	37.5	50.7
Cash and cash equivalents at end of period	$ 36.0	$ 37.0