Share Options And Awards (Narrative) (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended	12 Months Ended				12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2012 LT Incentive Plan Stock Options And Awards [Member]	Dec. 31, 2012 2010 Restated LT Incentive Plan Stock Options and Awards [Member]	Dec. 31, 2012 Share Options [Member]	Dec. 31, 2011 Share Options [Member]	Dec. 31, 2010 Share Options [Member]	Dec. 31, 2012 Restricted Shares [Member]	Dec. 31, 2011 Restricted Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option and share awards outstanding	4,085,702	4,607,703	4,614,272	4,436,143	3,400,000
Plan common shares authorized						3,000,000
Plan common shares available for future grants						1,900,000
Plan expiration date						May 06, 2020
Net compensation expense for share options and restricted shares	$ 9.7	$ 6.4	$ 4.9
Net capitalized compensation expense	2.0	1.5	1.2
Total intrinsic value of options exercised							3.0	1.9	1.8
Unrecognized compensation cost							$ 2.2	$ 3.8		$ 4.7	$ 5.0
Weighted average expected amortization period for unrecognized compensation cost (in years)							1 year 7 months	2 years 5 months		1 year 11 months	2 years 4 months