Earnings Per Share (Narrative) (Details) - $ / shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
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		$ 45.20	$ 51.64	$ 45.20
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit		$ 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	2,000	2,000	2,000	2,000
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	313	33	312	44