Earnings Per Common Share (Computation Of Basic And Diluted Net Earnings Per Share) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Earnings Per Share [Abstract]
Net income	$ 13,790	$ 11,517	$ 41,677	$ 31,416
Basic earnings per common share, Income (Numerator)	13,790	11,517	41,677	31,416
Basic earnings per common share, Shares (Denominator)	69,706	67,651	68,926	67,344
Basic earnings per common share (dollars per share)	$ 0.20	$ 0.17	$ 0.60	$ 0.47
Effect of dilutive securities, Options, Shares	825	984	832	972
Effect of dilutive securities, Options, (dollars per share)	$ 0.00	$ 0.00	$ 0.00	$ (0.01)
Diluted earnings per common share, Income (Numerator)	$ 13,790	$ 11,517	$ 41,677	$ 31,416
Diluted earnings per common share, Shares (Denominator)	70,531	68,635	69,758	68,316
Diluted earnings per common share (dollars per share)	$ 0.20	$ 0.17	$ 0.60	$ 0.46
Options outstanding to purchase common stock excluded from computation of diluted earnings per common share	547	507	548	559
Antidilutive securities excluded from earnings per share, average exercise price	$ 23.50	$ 17.50	$ 23.50	$ 17.50