Management Compensation Plans (Schedule of Performance-based RSUs Monte Carlo Simulation Valuation Assumptions) (Details) (Performance Restricted Stock Units (PRSUs) [Member])	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Performance Restricted Stock Units (PRSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	0.38%	0.79%	1.11%
Dividend yield	0.00 - 4.37%	0.00 - 4.18%	0.00 - 4.64%
Volatility	25 - 90%	25 - 70%	25 - 75%

If different dividend rates are used during the contractual term, then disclose the range of expected dividends used.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph e(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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 (f)(2)(iii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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