Refers to percentage of annual depreciation rate charge for property, plant and equipment.

No definition available.

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- Definition

The initial length of time that the company's long-term evergreen contracts in effect. Sales of PCC (precipitated calcium carbonate) are predominantly pursuant to long-term evergreen contracts, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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- Definition

The length of time for which a receivable is past due that will trigger an individual review for collectability, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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Period Type:	duration

- References

No definition available.

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Data Type:	xbrli:stringItemType
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- References

No definition available.

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Data Type:	xbrli:stringItemType
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Period Type:	duration

- Definition

Amount, after adjustment, of cost-method investment. Adjustments include, but are not limited to, dividends received in excess of earnings after date of investment that are considered a return of investment and other than temporary impairments.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- Definition

This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=66022249&loc=d3e33749-111570

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-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References

No definition available.

+ Details

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Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of investments including trading securities, available-for-sale securities, held-to-maturity securities, and short-term investments classified as other and current.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(2))
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-Name Accounting Standards Codification
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of investments, not including unrealized gains or losses on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity, held at each balance sheet date and included in earnings for the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

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Balance Type:	credit
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- Details

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- Details

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- Details

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- Details

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- Details

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Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Cash Equivalents and Short-term Investments [Abstract]
Short-term investments	$ 2.7	$ 2.0
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	$ 16.1
Cost method investment	$ 0.0
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