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, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income (Numerator)
Net income	$ 15,472		$ (22,182)		$ 13,921		$ 14,639		$ 5,452		$ 13,790		$ 12,933		$ 14,954		$ 21,850	$ 47,129	$ 44,214
Basic earnings per common share																	21,850	47,129	44,214
Diluted earnings per common share																	$ 21,850	$ 47,129	$ 44,214
Shares (Denominator)
Basic earnings per common share, Shares (Denominator)																	70,616	69,206	67,511
Effect of dilutive securities, options and restricted stock (in shares)																	725	839	974
Diluted earnings per common share (in shares)																	71,341	70,045	68,485
Per-share Amount
Basic earnings per common share (in dollars per share)	$ 0.22	[1]	$ (0.31)	[1]	$ 0.20	[1]	$ 0.21	[1]	$ 0.08	[1]	$ 0.20	[1]	$ 0.19	[1]	$ 0.22	[1]	$ 0.31	$ 0.68	$ 0.65
Effect of dilutive securities, options and restricted stock (in dollars per share)																	$ 0.00	$ (0.01)	$ 0.00
Diluted earnings per common share (in dollars per share)	$ 0.22	[1]	$ (0.31)	[1]	$ 0.20	[1]	$ 0.21	[1]	$ 0.08	[1]	$ 0.20	[1]	$ 0.19	[1]	$ 0.22	[1]	$ 0.31	$ 0.67	$ 0.65
Options outstanding to purchase common stock excluded from computation of diluted earnings per common share (in shares)																	494	546	576

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