Benefit Plans (Summary Of Restricted Stock Activity) (Details) (Performance Contingent Restricted Stock [Member], USD $)	9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Nonvested, January 1 (in shares/awards)	158,922		211,651
Nonvested shares, January 1, weighted average fair value (in dollars per share)	$ 42.71		$ 32.42
Granted (in shares/awards)	51,221		49,093
Granted, weighted average fair value (in dollars per share)	$ 53.77		$ 47.58
Vested (in shares/awards)	(90,847)	[1]	0	[1]
Vested, weighted average fair value (in dollars per share)	$ 40.91	[1]	$ 0.00	[1]
Forfeited (in shares/awards)	(20,484)	[2]	(101,822)	[2]
Forfeited, weighted average fair value (in dollars per share)	$ 39.85	[2]	$ 23.67	[2]
Nonvested, September 30 (in shares/awards)	98,812		158,922
Nonvested shares, September 30, weighted average fair value (in dollars per share)	$ 50.69		$ 42.71
2012 Grant [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Vested (in shares/awards)	(45,612)	[1]
2011 Grant [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Vested (in shares/awards)	(45,235)	[1]
2009 Grant [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Forfeited (in shares/awards)			(101,822)	[2]

[1] In 2014, 45,612 and 45,235 performance contingent restricted shares granted in 2012 and 2011, respectively, vested because the specified performance criteria for such shares were met.

[2] In 2013, 101,822 performance contingent restricted shares granted in 2009 were forfeited because the specified performance criteria for such shares were not met.