Goodwill and Other Intangible Assets (Schedule of Goodwill and Other Intangible Assets Included in Equity Method Investments) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Other intangible assets
Gross amount, End of Period	$ 58,399	$ 58,477
Accumulated impairment losses and amortization, End of Period	(43,424)	(39,560)
Other intangible assets, Net, End of Period	14,975	18,917
Goodwill and Other intangible assets, Total
Goodwill and Other intangible assets, Net, End of Period	7,902	8,111
Investments in other ventures
Goodwill
Goodwill, Gross amount, Beginning of Period	12,545	10,840
Accumulated impairment losses and amortization, Beginning of Period	0	0
Goodwill, Net, Beginning of Period	12,545	10,840
Acquired during the year		1,705
Adjustments to gross amounts	(227)
Goodwill, Gross amount, End of Period	12,318	12,545
Accumulated impairment losses and amortization, End of Period	0	0
Goodwill, Net, End of Period	12,318	12,545
Other intangible assets
Gross amount, Beginning of Period	45,478	44,323
Accumulated impairment losses and amortization, Beginning of Period	(28,811)	(24,769)
Other intangible assets, Net, Beginning of Period	16,667	19,554
Acquired during the year		1,155
Amortization	(3,655)	(4,042)
Adjustments to gross amounts	(78)
Gross amount, End of Period	45,400	45,478
Accumulated impairment losses and amortization, End of Period	(32,466)	(28,811)
Other intangible assets, Net, End of Period	12,934	16,667
Goodwill and Other intangible assets, Total
Gross amount, Beginning of Period	58,023	55,163
Accumulated impairment losses and amortization, Beginning of Period	(28,811)	(24,769)
Goodwill and Other intangible assets, Net, Beginning of Period	29,212	30,394
Acquired during the year		2,860
Amortization	(3,655)	(4,042)
Adjustments to gross amounts	305
Gross amount, End of Period	57,718	58,023
Accumulated impairment losses and amortization, End of Period	(32,466)	(28,811)
Goodwill and Other intangible assets, Net, End of Period	$ 25,252	$ 29,212

Goodwill and Intangible Assets, Accumulated Impairment and Amortization

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Goodwill and Intangible Assets, Acquired During Period

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Goodwill and Intangible Assets, Gross

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Intangible Assets (Excluding Goodwill), Accumulated Amortization and Impairment

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Intangible Assets, Net (Including Goodwill), Other Changes

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Intangible Assets, Other Changes

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The aggregate amount of recurring noncash expense charged against earnings in the period to allocate the cost of assets over their estimated remaining economic lives.

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The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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Amount of increase in assets, excluding financial assets, lacking physical substance with a definite life, resulting from a business combination.

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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

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Amount before accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of accumulated impairment loss for an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of other (increase) decrease of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount before accumulated amortization of intangible assets, excluding goodwill.

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Sum of the carrying amounts of all intangible assets, excluding goodwill, as of the balance sheet date, net of accumulated amortization and impairment charges.

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Carrying amount of finite-lived intangible assets, indefinite-lived intangible assets and goodwill. Goodwill is an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Intangible assets are assets, not including financial assets, lacking physical substance.

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