Stock-Based Compensation Plans (Restricted Shares Granted) (Details) (USD $)	6 Months Ended
Jun. 30, 2011
Grant Share Amount A [Member]
Restricted share grants, Date of Grant	January 4, 2011
Restricted share grants, Shares	475,804
Restricted share grants Market Value Per Share	$ 12.14
Restricted share grants vesting percentage	20.00%
Restricted share grants Vesting Period, in years	five
Grant Share Amount B [Member]
Restricted share grants, Date of Grant	January 4, 2011
Restricted share grants, Shares	4,427
Restricted share grants Market Value Per Share	$ 12.14
Restricted share grants vesting percentage	100.00%
Restricted stock, vesting date	January 1, 2013
Grant Share Amount C [Member]
Restricted share grants, Date of Grant	April 1, 2011
Restricted share grants, Shares	2,907
Restricted share grants Market Value Per Share	$ 17.20
Restricted share grants vesting percentage	100.00%
Restricted stock, vesting date	January 1, 2013
Grant Share Amount D [Member]
Restricted share grants, Date of Grant	May 11, 2011
Restricted share grants, Shares	21,608
Restricted share grants Market Value Per Share	$ 16.14
Restricted share grants vesting percentage	20.00%
Restricted share grants Vesting Period, in years	five

Share Based Compensation Arrangement By Share Based Payment Award Date Of Grant

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- Definition

Share Based Compensation Arrangement By Share Based Payment Award Vesting date

+ Details

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- Definition

Share Based Compensation Arrangement By Share Based Payment Award Vesting Percentage

+ Details

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- Definition

Description of the period of time over which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, which may be expressed in a variety of ways (for example, in years, month and year).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 123R
-Paragraph A240
-Subparagraph a
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 123R
-Paragraph A240
-Subparagraph b(2)(c)
-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 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

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- Definition

The weighted average of per share prices paid for shares purchased on the open market for issuance to employees under the plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

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Data Type:	num:perShareItemType
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