Fair Value Measurement (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
Jun. 30, 2012	Dec. 31, 2011
Level 3 \| Contingent consideration
Fair Value Inputs
Weighted average discount rate (as a percent)	12.00%	12.00%
Level 3 \| Contingent consideration \| Minimum
Fair Value Inputs
Probability of contingent consideration (as a percent)	5.00%	5.00%
Level 3 \| Contingent consideration \| Maximum
Fair Value Inputs
Probability of contingent consideration (as a percent)	95.00%	95.00%
Recurring basis \| Total Fair Value
Assets:
Interest Rate Cap	1	8
Recurring basis \| Total Fair Value \| Contingent consideration
Liabilities:
Due to seller	(4,605)	(6,498)
Recurring basis \| Level 2
Assets:
Interest Rate Cap	1	8
Recurring basis \| Level 3 \| Contingent consideration
Liabilities:
Due to seller	(4,605)	(6,498)

Percentage of likelihood the contingent consideration will be paid, used as an input to measure fair value.

No definition available.

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- Definition

Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bbb)

-URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258

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- Definition

Fair value as of the balance sheet date of interest rate derivative assets, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as assets.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 10

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=7491637&loc=d3e13433-108611

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 107

-Paragraph 10

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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- Definition

This element represents the aggregate of the liabilities reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258

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