Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014
Cash Equivalents and Short-term Investments [Abstract]
Short-term investments	$ 2.6	$ 2.6	$ 0.8
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
Property, Plant and Equipment [Abstract]
Initial term of long term evergreen contracts		10 years
Investment in joint ventures [Abstract]
Equity method investment	8.3	$ 8.3
Equity method investment, write-down in development stage	7.6
Cost method investments	$ 0.0	0.0
New accounting pronouncement or change in accounting principle effect from other long term assets to long term debt		$ 20.0
Buildings [Member]
Property, Plant and Equipment [Abstract]
Annual rates of depreciation, minimum		3.00%
Annual rates of depreciation, maximum		6.67%
Machinery and Equipment [Member]
Property, Plant and Equipment [Abstract]
Annual rates of depreciation, minimum		6.67%
Annual rates of depreciation, maximum		12.50%
Furniture and Fixtures [Member]
Property, Plant and Equipment [Abstract]
Annual rates of depreciation, minimum		8.00%
Annual rates of depreciation, maximum		12.50%
Computer Equipment and Software-related Assets [Member]
Property, Plant and Equipment [Abstract]
Annual rates of depreciation, minimum		12.50%
Annual rates of depreciation, maximum		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