Common Share Capitalization (Summary Of Common Shares Outstanding) (Details) - shares	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Shares Outstanding, period begin	32,294,703	33,126,012
Shares repurchased	(130,488)	(163,033)
Common Shares Outstanding, period end	32,164,215	32,962,979