Computation of 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
Net income:
Income from continuing operations	$ 307	$ 54,776	$ 2,164	$ 55,900
Income from discontinued operations		150		144
Net income	$ 307	$ 54,926	$ 2,164	$ 56,044
Shares outstanding:
Weighted-average common shares outstanding (in shares)	22,517	21,757	22,514	21,241
Additional dilutive common stock equivalents (in shares)	170	342	111	342
Diluted shares outstanding (in shares)	22,687	22,099	22,625	21,583
Basic net income per share:
Basic net income per share from continuing operations (in dollars per share)	$ 0.01	$ 2.51	$ 0.10	$ 2.63
Basic net income per share from discontinued operations (in dollars per share)	$ 0.00	$ 0.01	$ 0.00	$ 0.01
Basic net income per share (in dollars per share)	$ 0.01	$ 2.52	$ 0.10	$ 2.64
Diluted net income per share:
Diluted net income per share from continuing operations (in dollars per share)	$ 0.01	$ 2.48	$ 0.10	$ 2.59
Diluted net income per share from discontinued operations (in dollars per share)	$ 0.00	$ 0.01	$ 0.00	$ 0.01
Diluted net income per share (in dollars per share)	$ 0.01	$ 2.49	$ 0.10	$ 2.60