Related Party And Affiliate Transactions (Details) (USD $) In Thousands, unless otherwise specified	1 Months Ended		12 Months Ended
	Dec. 31, 2012	Mar. 31, 2000	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Sep. 30, 1997
Related Party Transaction [Line Items]
Due from affiliate, noncurrent	$ 1,192		$ 1,192	$ 2,383
Affiliates [Member]
Related Party Transaction [Line Items]
Incurred and paid lease payments			1,550	1,556	1,549
Suzhou Huasu Plastics Company, Ltd. [Member]
Related Party Transaction [Line Items]
Ownership interest	59.00%		59.00%
Percentage added to LIBOR for interest rate		2.00%
Loan to affiliates		2,000				5,150
Principal payments received	1,192			1,192
Interest received			74	441	934
Notes Receivable From Affiliate [Member] | Prepaid Expenses And Other Current Assets [Member] | Suzhou Huasu Plastics Company, Ltd. [Member]
Related Party Transaction [Line Items]
Due from affiliate, current	1,192		1,192
Notes Receivable From Affiliate [Member] | Other Assets, Net [Member] | Suzhou Huasu Plastics Company, Ltd. [Member]
Related Party Transaction [Line Items]
Due from affiliate, noncurrent	1,191		1,191
Cypress Interstate Pipeline L.L.C [Member] | Corporate Joint Venture [Member]
Related Party Transaction [Line Items]
Pipeline fees incurred for usage			$ 11,957	$ 9,474	$ 2,006