Equity Incentive Plans (Summary Of Share Option Activity) (Details) (USD $)	12 Months Ended											12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Minimum [Member]	Dec. 31, 2012 Minimum [Member]	Dec. 31, 2011 Minimum [Member]	Dec. 31, 2013 Maximum [Member]	Dec. 31, 2012 Maximum [Member]	Dec. 31, 2011 Maximum [Member]	Dec. 31, 2013 2007 Equity Incentive Plan [Member]	May 09, 2007 2007 Equity Incentive Plan [Member]	Dec. 31, 2013 Employee Stock Option [Member]	Dec. 31, 2012 Employee Stock Option [Member]	Dec. 31, 2011 Employee Stock Option [Member]	Dec. 31, 2013 Employee Stock Option [Member] Minimum [Member]	Dec. 31, 2012 Employee Stock Option [Member] Minimum [Member]	Dec. 31, 2013 Employee Stock Option [Member] Maximum [Member]	Dec. 31, 2012 Employee Stock Option [Member] Maximum [Member]
Common shares, options to purchase common shares and restricted share units, expected to granted											3,650,000
Number of shares available for grant										1,780,242
Maximum term of options granted, years	10 years
Exercisable rate for employees options, per year	25.00%
Share based compensation, future vesting period minimum (in years)	4 years			3 years			4 years					4 years
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of Shares, Outstanding at Beginning of Period	881,338	1,002,833	1,071,096
Number of Shares, Exercised	(143,272)	(224,181)	(135,196)
Number of Shares, Granted	115,257	103,082	70,266
Number of Shares, Forfeited	(12,658)	(396)	(3,333)
Number of Shares, Outstanding at End of Period	840,665	881,338	1,002,833
Share-based Compensation Arrangement by Share-based Payment Award, Options, Option Price Per Share [Roll Forward]
Option Price Per Share, Outstanding at Beginning of Period				$ 18.18	$ 18.18	$ 16.05	$ 65.50	$ 65.50	$ 65.50
Option Price Per Share, Exercised				$ 18.18	$ 18.18	$ 18.18	$ 47.20	$ 36.56	$ 42.46
Option Price Per Share, Granted				$ 46.86	$ 44.62	$ 45.73	$ 58.09	$ 47.99	$ 47.77
Option Price Per Share, Forfeited				$ 36.56	$ 18.18	$ 16.05	$ 60.42	$ 46.69	$ 16.05
Option Price Per Share, Outstanding at End of Period				$ 18.18	$ 18.18	$ 18.18	$ 65.50	$ 65.50	$ 65.50
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Average Exercise Price, Outstanding at Beginning of Period	$ 38.51	$ 34.41	$ 32.00
Average Exercise Price, Exercised	$ 30.64	$ 23.42	$ 21.96
Average Exercise Price, Granted	$ 47.86	$ 45.60	$ 46.19
Average Exercise Price, Forfeited	$ 56.90	$ 40.03	$ 16.05
Average Exercise Price, Outstanding at End of Period	$ 40.85	$ 38.51	$ 34.41
Weighted average fair value of options granted	$ 12.35	$ 12.08	$ 9.29
Intrinsic value of stock options exercised	$ 2,900,000	$ 5,100,000	$ 2,900,000
Shares Paid for Tax Withholding for Share Based Compensation	66,632
Payments Related to Tax Withholding for Share-based Compensation	3,400,000
Stock or Unit Option Plan Expense												$ 856,000	$ 937,000	$ 777,000
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Minimum												1.00%	1.10%	2.50%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Maximum													1.40%	3.10%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate														6.40%	5.40%	6.30%	6.50%	6.70%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Minimum																51.30%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum																		51.40%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate												50.70%		39.80%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Forfeiture Rate		0.25%	0.00%	0.23%			0.29%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term													6 years	8 years
option exercise period	1 year