Subsequent Events (Details) (Dividend Declared [Member], USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2011
Dividend Declared [Member]
Subsequent Event [Line Items]
Quarterly dividend, date declared	Feb. 09, 2012
Quarterly dividend, value per share	$ 0.07
Quarterly dividend, date to be paid	Mar. 09, 2012
Quarterly dividend, date of record	Feb. 21, 2012
Quarterly dividend, amount declared	$ 10.9

The day, month, and year (YYYY-MM-DD) that the dividend declared as of or prior to the financial reporting date will be paid in the subsequent period.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4304-108586

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Period Type:	duration

- Definition

The aggregate amount of dividends declared, but not paid, as of the financial reporting date.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 32

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 230

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4304-108586

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

The per share amount of a dividend declared, but not paid, as of the financial reporting date.

+ References

+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	na
Period Type:	instant

- Definition

The day, month and year (YYYY-MM-DD) that the dividend to be paid was declared.

+ References

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Namespace Prefix:	us-gaap_
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- Definition

The date as of when a holder must own the stock to be entitled to the dividend. The ex-dividend date is generally 3 days before the record date.

+ References

No definition available.

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