Description Of Business And Significant Accounting Policies (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Undistributed earnings included in retained earnings	$ 11,026
Capitalized interest	7,706	693	22
Goodwill	29,990	29,990
Amortization period, minimum (in years)	3 years
Amortization period, maximum (in years)	6 years
Other assets amortization period, minimum (in years)	1 year
Other assets amortization period, maximum (in years)	20 years
Exchange receivable (payable), net	$ 8,674	$ 14,557
PVC Joint Venture In China [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Ownership interest	59.00%
Natural Gas Pipeline Joint Venture [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Ownership interest	50.00%