Equity Incentive Plans (Summary Of Nonvested Share Activity) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Number of Shares, Outstanding at December 31, 2012	322,808
Number of Shares, Granted	198,833
Number of Shares, Vested	(145,570)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	(4,207)
Number of Shares, Outstanding at December 31, 2013	371,864	322,808
Weighted Average Grant Date Fair Value, Outstanding at December 31, 2012	$ 42.52
Weighted Average Grant Date Fair Value, Granted	$ 47.15
Weighted Average Grant Date Fair Value, Vested	$ 39.88
Weighted Average Grant Date Fair Value, Outstanding at December 31, 2013	$ 46.00	$ 42.52
Weighted Average Life Remaining, Outstanding at December 31, 2013	11 months 26 days
Share based compensation, future vesting period minimum (in years)	4 years
Fair value of non-vested shares	$ 6,700,000	$ 7,700,000	$ 7,300,000
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Share-based Awards Other than Options	$ 8,259,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price	$ 45.39
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Share based compensation, future vesting period minimum (in years)	4 years