Debt - 2012 Credit Agreement (Details Textual)	12 Months Ended
Dec. 31, 2012 USD ($)
2012 Credit Agreement
Debt Instrument [Line Items]
Credit Agreement	$ 250,000,000
2012 Credit Agreement \| Minimum
Debt Instrument [Line Items]
Basis spread on term loan	2.00%
2012 Credit Agreement \| Maximum
Debt Instrument [Line Items]
Basis spread on term loan	2.75%
2012 Credit Agreement \| Term Loan 2012 \| Minimum
Debt Instrument [Line Items]
Basis spread on term loan	1.00%
2012 Credit Agreement \| Term Loan 2012 \| Maximum \| Base Rate
Debt Instrument [Line Items]
Basis spread on term loan	1.75%
2012 Credit Agreement Term Loan
Debt Instrument [Line Items]
Credit Agreement	$ 150,000,000
Credit agreement period	5 years
Term loan combined interest rate	2.25%
2012 Credit Agreement Revolving Loan
Debt Instrument [Line Items]
Credit Agreement	$ 100,000,000
Credit agreement period	5 years

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

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- Definition

The average effective interest rate during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Period Type:	instant

- Details

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- Details

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- Details

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