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																12 Months Ended
	Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income (Numerator)
Net income	$ 5,452		$ 13,790		$ 12,933		$ 14,954		$ 12,798		$ 11,517		$ 11,320		$ 8,579		$ 47,129	$ 44,214	$ 38,156
Basic earnings per common share																	47,129	44,214	38,156
Diluted earnings per common share																	$ 47,129	$ 44,214	$ 38,156
Shares (Denominator)
Basic earnings per common share, Shares (Denominator)																	69,206	67,511	66,637
Effect of dilutive securities, options and restricted stock (in shares)																	839	974	948
Diluted earnings per common share (in shares)																	70,045	68,485	67,585
Per-share Amount
Basic earnings per common share (in dollars per share)	$ 0.08	[1]	$ 0.20	[1]	$ 0.19	[1]	$ 0.22	[1]	$ 0.19	[1]	$ 0.17	[1]	$ 0.17	[1]	$ 0.13	[1]	$ 0.68	$ 0.65	$ 0.57
Effect of dilutive securities, options and restricted stock (in dollars per share)																	$ (0.01)	$ 0.00	$ (0.01)
Diluted earnings per common share (in dollars per share)	$ 0.08	[1]	$ 0.20	[1]	$ 0.19	[1]	$ 0.22	[1]	$ 0.19	[1]	$ 0.17	[1]	$ 0.17	[1]	$ 0.13	[1]	$ 0.67	$ 0.65	$ 0.56
Options outstanding to purchase common stock excluded from computation of diluted earnings per common share (in shares)																	546	576	510

[1] Year-to-date earnings and cash dividends per common share amounts may differ from the sum of quarterly amounts due to rounding.