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Related Party And Affiliate Transactions (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended			1 Months Ended	5 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2000	Dec. 31, 2014	Sep. 30, 1997
Related Party Transaction [Line Items]
Proceeds from Equity Method Investment, Dividends or Distributions	$ 5,459	$ 5,114	$ 4,449
Due from affiliate, noncurrent	1,025us-gaap_DueFromAffiliateNoncurrent	1,025us-gaap_DueFromAffiliateNoncurrent			1,025us-gaap_DueFromAffiliateNoncurrent
Affiliates [Member]
Related Party Transaction [Line Items]
Incurred and paid lease payments	2,001	1,614	1,550
Cypress Interstate Pipeline L.L.C [Member]
Related Party Transaction [Line Items]
Ownership interest	50.00%				50.00%
American Air Liquide Holdings, Inc. [Member]
Related Party Transaction [Line Items]
Due to related parties	13,862	16,407
Cypress Interstate Pipeline L.L.C [Member] \| Corporate Joint Venture [Member]
Related Party Transaction [Line Items]
Pipeline fees incurred for usage	14,206	13,328	11,957
InfraServ Knapsack GmbH & Co. KG [Member] \| Affiliates [Member]
Related Party Transaction [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent	15.00%				15.00%
InfraServ Gendorf GmbH & Co. KG [Member] \| Affiliates [Member]
Related Party Transaction [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent	11.00%				11.00%
EPS Ethylene Pipeline Süd GmbH & Co. KG [Member] \| Affiliates [Member]
Related Party Transaction [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent	10.00%				10.00%
Suzhou Huasu Plastics Company Ltd [Member] \| Affiliates [Member]
Related Party Transaction [Line Items]
Ownership interest	59.00%				59.00%
Purchases from related parties	9,766	12,104
Loan to affiliates				2,000		5,150
Percentage added to LIBOR for interest rate				2.00%
Principal payments received	0	167	1,192
Interest received	0	8	74
Suzhou Huasu Plastics Company Ltd [Member] \| Notes Receivable From Affiliate [Member] \| Prepaid Expenses And Other Current Assets [Member] \| Affiliates [Member]
Related Party Transaction [Line Items]
Due from affiliate, current	1,192				1,192
Suzhou Huasu Plastics Company Ltd [Member] \| Notes Receivable From Affiliate [Member] \| Other Assets, Net [Member] \| Affiliates [Member]
Related Party Transaction [Line Items]
Due from affiliate, noncurrent	1,025				1,025
Electricity And Technical Services [Member] \| Affiliates [Member]
Related Party Transaction [Line Items]
Purchases from related parties					55,400
Pipeline Fees For Transport Of Ethylene Feedstocks [Member] \| EPS Ethylene Pipeline Süd GmbH & Co. KG [Member] \| Affiliates [Member]
Related Party Transaction [Line Items]
Purchases from related parties					$ 548