Shareholders Equity (Schedule Of Changes In Non-Vested Restricted Shares) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012
Shareholders' Equity
Non-vested shares at beginning of period, Number of Shares	732,412
Non-vested shares at beginning of period, Weighted Average Grant Price	$ 21.91
Shares granted, Number of Shares	255,138
Shares granted, Weighted Average Grant Price	$ 22.66
Shares vested, net of shares repurchased to cover tax withholding requirements,, Number of Shares	(166,078)
Shares vested, net of shares repurchased to cover tax withholding requirements, , Weighted Average Grant Price	$ 26.24
Shares forfeited, Number of Shares	(448)
Shares forfeited, Weighted Average Grant Price	$ 24.75
Non-vested shares at end of period, Number of Shares	821,024
Non-vested shares at end of period, Weighted Average Grant Price	$ 22.36