Equity Compensation Plans (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Equity Compensation Plans
Target payout percentage cash			50.00%
Target payout percentage stock			50.00%
Tax benefits associated with stock-based compensation	$ 2.9	$ 2.0	$ 5.2	$ 4.0

The total recognized tax benefit related to compensation cost for share-based payment arrangements recognized in income during the period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 123R
-Paragraph A240
-Subparagraph g(1)

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Data Type:	xbrli:monetaryItemType
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