Nominal number of units used to calculate payment on derivative.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5579245-113959

Name:	us-gaap_DerivativeNonmonetaryNotionalAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

Derivatives Derivatives - Schedule of Derivative Positions (Natural Gas) (Details) - Natural Gas Swaps [Member] - Not Designated as Hedging Instrument [Member] - Specialty Product [Member]	Jun. 30, 2020 MMBTU	Jun. 30, 2020 $ / MMBtu	Dec. 31, 2019 MMBTU
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	3,036,000	2.16	0
Third Quarter 2020
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	1,518,000	2.08
Fourth Quarter 2020
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	1,518,000	2.25