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		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Earnings Per Share [Abstract]
Net income	$ 12,933	$ 11,320	$ 27,887	$ 19,899
Basic earnings per common share, Income (Numerator)	12,933	11,320	27,887	19,899
Basic earnings per common share, Shares (Denominator)	68,599	67,296	68,531	67,189
Basic earnings per common share (dollars per share)	$ 0.19	$ 0.17	$ 0.41	$ 0.30
Effect of dilutive securities, Options, Shares	771	932	835	966
Effect of dilutive securities, Options, (dollars per share)	$ 0.00	$ 0.00	$ (0.01)	$ (0.01)
Diluted earnings per common share, Income (Numerator)	$ 12,933	$ 11,320	$ 27,887	$ 19,899
Diluted earnings per common share, Shares (Denominator)	69,370	68,228	69,366	68,155
Diluted earnings per common share (dollars per share)	$ 0.19	$ 0.17	$ 0.40	$ 0.29
Options outstanding to purchase common stock excluded from computation of diluted earnings per common share	552	596	548	585
Antidilutive securities excluded from earnings per share, average exercise price	$ 23.50	$ 17.50	$ 23.50	$ 17.50