Share-Based Compensation (Narrative) (Details)	3 Months Ended
Mar. 31, 2012 Y
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period of restricted stock and restricted stock units, vesting years	3
Options Granted Prior To 2008 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option vesting term, minimum years	four
Option vesting term, maximum years	five
Options Granted Subsequent To January 1, 2008 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option vesting term, years	four

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).

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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