Share-Based Compensation (Narrative) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified			3 Months Ended
Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2012 Maximum [Member]	Mar. 31, 2012 Minimum [Member]
Accrued liabilities for cash-settled	$ 4.2	$ 3.1
Weighted-average fair value per SAR	$ 13.33	$ 10.85
Percentage of grant target award recipients receive depending on performance criteria			200.00%	0.00%

Carrying value as of the balance sheet date of obligations incurred through that date and payable for employer-related costs not otherwise specified in the taxonomy.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 9

-Section 03

-Paragraph 15

-Subparagraph 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.15(5))

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.15(a))

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 7

-Section 03

-Paragraph 15

-Subparagraph a

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