Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash Equivalents and Short-term Investments [Abstract]
Short-term investments	$ 1.6	$ 3.8
Unrealized holding gains and losses on short-term bank investments	$ 0.0
Trade Accounts Receivable [Abstract]
Past due threshold for individual collectability review	90 days
Allowance for doubtful accounts	$ 12.9	3.2
Property, Plant and Equipment [Abstract]
Initial term of long term evergreen contracts	10 years
Investment in Joint Ventures [Abstract]
Equity method investment	$ 16.1
Recently Adopted Accounting Standards [Abstract]
Operating liabilities	11.9
Right-of-use assets	44.8
Operating Income (Loss) [Abstract]
Marketing and administrative expenses	(187.5)	(178.6)	$ (180.7)
Other deductions	$ (8.2)	(1.5)	$ (6.2)
Buildings [Member] | Minimum [Member]
Property, Plant and Equipment [Abstract]
Annual rates of depreciation	3.00%
Buildings [Member] | Maximum [Member]
Property, Plant and Equipment [Abstract]
Annual rates of depreciation	6.67%
Machinery and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Abstract]
Annual rates of depreciation	6.67%
Machinery and Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Abstract]
Annual rates of depreciation	12.50%
Furniture and Fixtures [Member] | Minimum [Member]
Property, Plant and Equipment [Abstract]
Annual rates of depreciation	8.00%
Furniture and Fixtures [Member] | Maximum [Member]
Property, Plant and Equipment [Abstract]
Annual rates of depreciation	12.50%
Computer Equipment and Software-related Assets [Member] | Minimum [Member]
Property, Plant and Equipment [Abstract]
Annual rates of depreciation	12.50%
Computer Equipment and Software-related Assets [Member] | Maximum [Member]
Property, Plant and Equipment [Abstract]
Annual rates of depreciation	25.00%
PCC Production Facilities [Member]
Property, Plant and Equipment [Abstract]
Estimated useful life	15 years
Machinery and Equipment for Natural Stone Mining and Processing Plants and Chemical Plants [Member]
Property, Plant and Equipment [Abstract]
Estimated useful life	15 years
ASU 2016-02 [Member]
Recently Adopted Accounting Standards [Abstract]
Operating liabilities		61.4
Right-of-use assets		50.5
Deferred charges		10.9
ASU 2018-02 [Member]
Recently Adopted Accounting Standards [Abstract]
Reclassification of certain tax effects from accumulated other comprehensive income		0.0
ASU 2018-02 [Member] | Accumulated Other Comprehensive Loss [Member]
Recently Adopted Accounting Standards [Abstract]
Reclassification of certain tax effects from accumulated other comprehensive income	$ (10.9)	(10.9)
ASU 2018-02 [Member] | Retained Earnings [Member]
Recently Adopted Accounting Standards [Abstract]
Reclassification of certain tax effects from accumulated other comprehensive income	$ 10.9	$ 10.9