Special Cash Dividend And Stock Option Adjustments (Summary Of The Adjustments To Options Outstanding) (Details) (Special Cash Dividend [Member], USD $)	Sep. 30, 2012
Granted 2006 [Member] | Pre-Dividend Grant Terms [Member]
Special Cash Dividend And Stock Option Adjustments [Line Items]
Number of Shares	262,418
Exercise Price	$ 22.55
Granted 2006 [Member] | Post-Dividend Grant Terms [Member]
Special Cash Dividend And Stock Option Adjustments [Line Items]
Number of Shares	305,992
Exercise Price	$ 19.34
Granted 2007 [Member] | Pre-Dividend Grant Terms [Member]
Special Cash Dividend And Stock Option Adjustments [Line Items]
Number of Shares	83,452
Exercise Price	$ 30.62
Granted 2007 [Member] | Post-Dividend Grant Terms [Member]
Special Cash Dividend And Stock Option Adjustments [Line Items]
Number of Shares	97,306
Exercise Price	$ 26.26
Granted 2008 [Member] | Pre-Dividend Grant Terms [Member]
Special Cash Dividend And Stock Option Adjustments [Line Items]
Number of Shares	171,792
Exercise Price	$ 21.85
Granted 2008 [Member] | Post-Dividend Grant Terms [Member]
Special Cash Dividend And Stock Option Adjustments [Line Items]
Number of Shares	200,318
Exercise Price	$ 18.74
Granted 2009 [Member] | Pre-Dividend Grant Terms [Member]
Special Cash Dividend And Stock Option Adjustments [Line Items]
Number of Shares	100,209
Exercise Price	$ 10.34
Granted 2009 [Member] | Post-Dividend Grant Terms [Member]
Special Cash Dividend And Stock Option Adjustments [Line Items]
Number of Shares	116,851
Exercise Price	$ 8.87
Granted 2010 [Member] | Pre-Dividend Grant Terms [Member]
Special Cash Dividend And Stock Option Adjustments [Line Items]
Number of Shares	608,278
Granted 2010 [Member] | Post-Dividend Grant Terms [Member]
Special Cash Dividend And Stock Option Adjustments [Line Items]
Number of Shares	709,309
Granted 2010 [Member] | Minimum [Member] | Pre-Dividend Grant Terms [Member]
Special Cash Dividend And Stock Option Adjustments [Line Items]
Exercise Price	$ 26.21
Granted 2010 [Member] | Minimum [Member] | Post-Dividend Grant Terms [Member]
Special Cash Dividend And Stock Option Adjustments [Line Items]
Exercise Price	$ 22.48
Granted 2010 [Member] | Maximum [Member] | Pre-Dividend Grant Terms [Member]
Special Cash Dividend And Stock Option Adjustments [Line Items]
Exercise Price	$ 29.23
Granted 2010 [Member] | Maximum [Member] | Post-Dividend Grant Terms [Member]
Special Cash Dividend And Stock Option Adjustments [Line Items]
Exercise Price	$ 25.07
Granted 2011 [Member] | Pre-Dividend Grant Terms [Member]
Special Cash Dividend And Stock Option Adjustments [Line Items]
Number of Shares	434,674
Granted 2011 [Member] | Post-Dividend Grant Terms [Member]
Special Cash Dividend And Stock Option Adjustments [Line Items]
Number of Shares	506,873
Granted 2011 [Member] | Minimum [Member] | Pre-Dividend Grant Terms [Member]
Special Cash Dividend And Stock Option Adjustments [Line Items]
Exercise Price	$ 38.65
Granted 2011 [Member] | Minimum [Member] | Post-Dividend Grant Terms [Member]
Special Cash Dividend And Stock Option Adjustments [Line Items]
Exercise Price	$ 33.15
Granted 2011 [Member] | Maximum [Member] | Pre-Dividend Grant Terms [Member]
Special Cash Dividend And Stock Option Adjustments [Line Items]
Exercise Price	$ 47.47
Granted 2011 [Member] | Maximum [Member] | Post-Dividend Grant Terms [Member]
Special Cash Dividend And Stock Option Adjustments [Line Items]
Exercise Price	$ 40.71
Granted 2012 [Member] | Pre-Dividend Grant Terms [Member]
Special Cash Dividend And Stock Option Adjustments [Line Items]
Number of Shares	403,750
Exercise Price	$ 50.38
Granted 2012 [Member] | Post-Dividend Grant Terms [Member]
Special Cash Dividend And Stock Option Adjustments [Line Items]
Number of Shares	470,805
Exercise Price	$ 43.21