Share-Based Compensation (Summary Of ESPP Annual Offerings) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount expensed under ESPP	$ 2,538	[1]	$ 2,152	[1]	$ 1,332	[1]
ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares purchased	79		71		75
Per common share purchase Price	$ 15.04		$ 13.83		$ 12.07
Amount expensed under ESPP	641		282		317
Net proceeds from issuance	$ 1,192		$ 978		$ 911
Common shares date of issue	Jan. 4, 2013		Jan. 4, 2012		Jan. 6, 2011

[1] Stock-based compensation expense is recorded in the selling, general and administrative caption in our consolidated statements of comprehensive income.