Earnings Per Share (Computation Of Basic And Diluted Earnings Per Share) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Numerator (both basic and diluted):
Net income (loss)	$ (6,956)	$ 6,663	$ (28,530)	$ 39,389
Denominator:
Denominator for basic earnings per share	40,400,082	40,227,407	40,494,628	40,713,950
Stock options		140,849		177,873
Unvested restricted stock		72,849		568,532
Denominator for diluted earnings per share	40,400,082	40,441,105	40,494,628	41,460,355
Basic earnings per common share:	$ (0.17)	$ 0.17	$ (0.70)	$ 0.97
Diluted earnings per common share:	$ (0.17)	$ 0.16	$ (0.70)	$ 0.95