Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Supplemental Schedule of Noncash Investing and Financing Activities
Cash dividends declared, but not yet paid		$ 4.1	$ 4.2
Settlement of accounts receivable balance owed to company		8.1
Assets acquired, net of cash	[1]	103.4	30.6
Liabilities assumed	[1]	$ 7.7	1.0
Acquisitions, 2016
Supplemental Schedule of Noncash Investing and Financing Activities
Promissory note issued for acquisition			$ 0.5

[1] Amounts may not add due to rounding