Significant Accounting Policies (Schedule Of Basic Weighted Average Shares Reconciles To Diluted Weighted Average Shares) (Details) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Significant Accounting Policies [Abstract]
Basic weighted average common shares outstanding	82,596	82,402	82,151	81,430	80,899	80,517	80,369	80,080	82,145	80,466	79,716
Dilutive effect of stock options, DCUs and unvested shares									1,398	1,517	1,011
Diluted weighted average common shares outstanding	83,573	83,586	83,778	83,248	82,686	81,938	81,800	81,509	83,543	81,983	80,727