Partners' Capital, Mezzanine Equity and Distributions (Redeemable Noncontrolling Interest- Narrative) (Details)			3 Months Ended	12 Months Ended
	Apr. 14, 2020 USD ($) shares	Sep. 23, 2019 USD ($) manager d $ / shares shares	Dec. 31, 2019 USD ($) shares	Dec. 31, 2020 USD ($) shares	Dec. 31, 2019 USD ($) shares	Dec. 31, 2018 USD ($)
Redeemable Noncontrolling Interest [Line Items]
Issuance of Preferred Units		$ 55,000,000
Redeemable Noncontrolling Interest, Equity, Preferred Units, Units issued | shares				9,499
Net income attributable to redeemable noncontrolling interests				$ (16,113,000)	$ (2,233,000)	$ 0
Distribution paid-in-kind			$ 1,750,000	13,811,000
Redemption accretion			$ 483,000	$ 2,302,000
Redeemable Non Controlling Interest
Redeemable Noncontrolling Interest [Line Items]
Convertible preferred units outstanding (in units) | shares			130,000	141,249	130,000
Genesis Alkali Holdings Company, LLC [Member] | Redeemable Non Controlling Interest
Redeemable Noncontrolling Interest [Line Items]
Convertible preferred units outstanding (in units) | shares				141,249
Genesis Alkali Holdings Company, LLC [Member] | Subsidiaries [Member]
Redeemable Noncontrolling Interest [Line Items]
Issuance of Preferred Units		$ 55,000,000
Redeemable Noncontrolling Interest, Equity, Preferred, Commitment Period	4 years	3 years
Facility Expansion Costs, Funding Percentage		100.00%
Redeemable Noncontrolling Interest, Project Extension Period	1 year
Redeemable Noncontrolling Interest, Equity, Preferred Units, Units issued | shares	1,750
Redeemable Noncontrolling Interest, Equity, Preferred, Annual Percentage For Quarterly Distributions		10.00%
Redeemable Noncontrolling Interest, Equity, Preferred, Liquidation Preference Per Unit | $ / shares		$ 1,000
Redeemable Noncontrolling Interest, Equity, Preferred, Days In Period After End Of Fiscal Quarter To Pay Cash Distributions | d		45
Redeemable Noncontrolling Interest, Equity, Preferred, Period After Initial Closing Date To Pay Distributions Paid-in-kind		48 months
Redeemable Noncontrolling Interest, Equity, Preferred, Minimum Cash Reserve Balance		$ 5,000,000
Redeemable Noncontrolling Interest, Equity, Preferred, Purchase Price Per Unit | $ / shares		$ 1,000
Redeemable Noncontrolling Interest, Equity, Preferred, Period For Triggering Event To Occur		6 years 6 months
Net income attributable to redeemable noncontrolling interests				$ (16,100,000)	$ (2,300,000)
Distribution paid-in-kind				13,800,000	1,800,000
Redemption accretion				2,300,000	$ 500,000
Redeemable Noncontrolling Interest, Equity, Preferred, Fair Value				$ 194,800,000
Genesis Alkali Holdings Company, LLC [Member] | Subsidiaries [Member] | Redeemable Non Controlling Interest
Redeemable Noncontrolling Interest [Line Items]
Convertible preferred units outstanding (in units) | shares		55,000
Minimum | Genesis Alkali Holdings Company, LLC [Member] | Subsidiaries [Member]
Redeemable Noncontrolling Interest [Line Items]
Redeemable Noncontrolling Interest, Equity, Preferred, Amount Authorized		$ 251,750,000
Number Board Of Managers | manager		5
Number Of Board Managers Designated By The Partnership | manager		3
Number Of Board Managers Designated By The Sponsor | manager		1
Number Of Independent Board Managers | manager		1
Maximum | Genesis Alkali Holdings Company, LLC [Member] | Subsidiaries [Member]
Redeemable Noncontrolling Interest [Line Items]
Convertible preferred units outstanding (in units) | shares	351,750	350,000
Redeemable Noncontrolling Interest, Equity, Preferred, Amount Authorized	$ 351,750,000	$ 350,000,000