Earnings Per Share (Narrative) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 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	$ 45.20
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$ 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
Preferred share dividend percentage	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
Preferred share dividend percentage	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	417	358