Earnings Per Share (Narrative) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Anitidlutive securities exluded from computation of earnings per share [Line Items]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$ 46.86	$ 45.20	$ 45.20	$ 45.20
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$ 65.50	$ 65.50	$ 65.50	$ 65.50
Series C Cumulative Convertible Preferred Share [Member]
Anitidlutive securities exluded from computation of earnings per share [Line Items]
Common shares upon conversion of convertible preferred shares	1,900	1,900	1,900	1,900
Preferred share dividend percentage	5.75%	5.75%	5.75%	5.75%
Series E Cumulative Convertible Preferred Share [Member]
Anitidlutive securities exluded from computation of earnings per share [Line Items]
Common shares upon conversion of convertible preferred shares	1,600	1,600	1,600	1,600
Preferred share dividend percentage	9.00%	9.00%	9.00%	9.00%
Share Options [Member]
Anitidlutive securities exluded from computation of earnings per share [Line Items]
Common shares upon conversion of convertible preferred shares	279	331	378	331