Earnings Per Common Share (Computation Of Basic And Diluted Net Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Earnings Per Share [Abstract]
Net income	$ 16,288	$ 13,921	$ 31,804	$ 28,560
Basic earnings per common share, Income (Numerator)	$ 16,288	$ 13,921	$ 31,804	$ 28,560
Basic earnings per common share, Shares (Denominator)	71,657	70,440	71,563	70,381
Basic earnings per common share (dollars per share)	$ 0.23	$ 0.20	$ 0.44	$ 0.41
Effect of dilutive securities, Stock options and restricted stock, Shares (Denominator)	629	766	660	759
Effect of dilutive securities, Stock options and restricted stock (dollars per share)	$ 0.00	$ 0.00	$ 0.00	$ (0.01)
Diluted earnings per common share, Income (Numerator)	$ 16,288	$ 13,921	$ 31,804	$ 28,560
Diluted earnings per common share, Shares (Denominator)	72,286	71,206	72,223	71,140
Diluted earnings per common share (dollars per share)	$ 0.23	$ 0.20	$ 0.44	$ 0.40
Options outstanding to purchase common stock excluded from computation of diluted earnings per common share (shares)	1,015	578	1,014	785
Antidilutive securities excluded from earnings per share, average exercise price (dollars per share)	$ 29.25	$ 27.56	$ 29.23	$ 26.49