Accounting Policies - Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011
Accounting Policies [Abstract]
Net (loss)/income attributable to common stockholders, basic	$ (4,291)		$ 5,170		$ 17,912		$ 23,493
Weighted-average shares, basic (shares)	10,468		10,343		10,417		10,314
Basic (loss)/earnings per common share (dollars per share)	$ (0.41)		$ 0.50		$ 1.72		$ 2.28
Weighted-average shares, dilutive securities, stock options, SARs, and restricted stock (shares)	0	[1]	376	[1]	545	[2]	378	[2]
Earnings Per Share, dilutive securities, stock options, SARs, and restricted stock (dollars per share)	$ 0.00	[1]	$ (0.02)	[1]	$ (0.09)	[2]	$ (0.08)	[2]
Net (loss)/Income income attributable to common stockholders, diluted	$ (4,291)		$ 5,170		$ 17,912		$ 23,493
Weighted-average shares, diluted (shares)	10,468		10,719		10,962		10,692
Diluted (loss)/earnings per common share (dollars per share)	$ (0.41)		$ 0.48		$ 1.63		$ 2.20

[1] For the three months ended June 30, 2012 and 2011, stock options and SARs of 1,270,777 and 652,234, respectively, were outstanding but not included in the computation of diluted earnings per share of common stock because they were anti-dilutive. For the three months ended June 30, 2012 and 2011, contingent shares of non-vested restricted stock of 146,311 and 170,760, respectively, were outstanding but not included in the computation of diluted earnings per share of common stock because performance conditions were not me

[2] )For the six months ended June 30, 2012 and 2011, stock options and SARs of 469,577 and 705,515, respectively, were outstanding but not included in the computation of diluted earnings per share of common stock because they were anti-dilutive. For the six months ended June 30, 2012 and 2011, contingent shares of non-vested restricted stock of 92,800 and 148,380, respectively, were outstanding but not included in the computation of diluted earnings per share of common stock because performance conditions were not me