Equity Investments and Membership Interests in Joint Ventures (Summarized Financial Information of Equity Method Investments) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investment, Summarized Financial Information, Revenue	$ 208,289	$ 190,661	$ 184,358
Equity Method Investment, Summarized Financial Information, Gross Profit (Loss)	10,234	15,308	19,495
Equity Method Investment, Summarized Financial Information, Income (Loss) from Continuing Operations before Extraordinary Items	6,574	8,898	13,180
Equity Method Investment, Summarized Financial Information, Net Income (Loss)	(397)	641	6,788
Equity Method Investment, Summarized Financial Information, Current Assets	52,413	78,961
Equity Method Investment, Summarized Financial Information, Noncurrent Assets	398,495	387,884
Equity Method Investment, Summarized Financial Information, Assets	450,908	466,845
Equity Method Investment, Summarized Financial Information, Current Liabilities	31,243	57,403
Equity Method Investment, Summarized Financial Information, Noncurrent Liabilities	131,445	128,489
Equity Method Investment Summarized Financial Information, Equity	287,903	280,690
Equity Method Investment, Summarized Financial Information, Noncontrolling Interest	317	263
Equity Method Investment, Summarized Financial Information, Liabilities and Equity	$ 450,908	$ 466,845

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The amount of assets reported by an equity method investment of the entity.

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The amount of current assets reported by an equity method investment of the entity.

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The amount of current liabilities reported by an equity method investment of the entity.

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Amount of equity, including noncontrolling interest, reported by an equity method investment of the entity.

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The amount of gross profit (loss) reported by an equity method investment of the entity.

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The amount of income (loss) from continuing operations before extraordinary items reported by an equity method investment of the entity.

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The amount of liabilities and equity reported by an equity method investment of the entity.

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Amount of equity attributable to noncontrolling interests of an equity method investment of the entity.

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The amount of net income (loss) reported by an equity method investment of the entity.

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The amount of noncurrent assets reported by an equity method investment of the entity.

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The amount of noncurrent liabilities reported by an equity method investment of the entity.

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The amount of revenue from sale of goods and services reduced by sales returns, allowances, and discounts reported by an equity method investment of the entity.

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