Earnings per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	9 Months Ended		15 Months Ended
	Sep. 30, 2012	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012
Earnings Per Share, Basic and Diluted
Net income (loss)	$ (1,105)	$ 3,182	$ 32,445	$ 8,406
Weighted average shares outstanding	39,575	39,441	37,431	39,322
Weighted average shares outstanding for diluted net income (loss) per share	39,575	40,243	38,120	39,976
Basic net income (loss) per share (in dollars per share)	$ (0.03)	$ 0.08	$ 0.87	$ 0.21
Diluted net income (loss) per share (in dollars per share)	$ (0.03)	$ 0.08	$ 0.85	$ 0.21
Stock Options [Member]
Earnings Per Share, Basic and Diluted
Weighted average shares outstanding, adjustment	0	10	22	16
Excluded from the diluted EPS calculation because their effect would be anti-dilutive	52	52	82	67
Restricted Stock [Member]
Earnings Per Share, Basic and Diluted
Weighted average shares outstanding, adjustment	0	792	667	638
Excluded from the diluted EPS calculation because their effect would be anti-dilutive	105	105	766	766