Intangible Assets (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2012
Assets [Member]
Annual amortization of intangible assets and liabilities
2012	$ 13,970
2013	12,414
2014	9,587
2015	7,193
2016	4,561
Thereafter	16,244
Total	63,969
Liabilities [Member]
Annual amortization of intangible assets and liabilities
2012	5,054
2013	6,312
2014	4,745
2015	2,597
2016	1,704
Thereafter	12,866
Total	$ 33,278

The aggregate estimated amortization expense for succeeding fiscal years for intangible assets subject to amortization.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 45

-Subparagraph a(3)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(3)

-URI http://asc.fasb.org/extlink&oid=6905858&loc=d3e16323-109275

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- Definition

The amount of amortization expense expected to be recognized for the remainder of the finite-lived intangible asset useful life after the fifth succeeding fiscal year.

+ References

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- Definition

The amount of amortization expense expected to be recognized during year five of the five succeeding fiscal years.

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The amount of amortization expense expected to be recognized during year four of the five succeeding fiscal years.

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The amount of amortization expense expected to be recognized during year one of the five succeeding fiscal years.

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- Definition

The amount of amortization expense expected to be recognized during year three of the five succeeding fiscal years.

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The amount of amortization expense expected to be recognized during year two of the five succeeding fiscal years.

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