Accounting Policies - Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011
Accounting Policies [Abstract]
Net income/(loss) attributable to common stockholders	$ 16,381		$ (23,032)		$ 34,293		$ 461
Weighted-average shares, basic (shares)	10,492		10,354		10,442		10,328
Basic earnings/(loss) per common share (dollars per share)	$ 1.56		$ (2.22)		$ 3.28		$ 0.04
Weighted-average shares, dilutive securities, stock options, SARs, and restricted stock (shares)	504	[1]	0	[1]	532	[2]	387	[2]
Earnings Per Share, dilutive securities, stock options, SARs, and restricted stock (dollars per share)	$ (0.07)	[1]	$ 0.00	[1]	$ (0.16)	[2]	$ 0.00	[2]
Net (loss)/Income income attributable to common stockholders, diluted	$ 16,381		$ (23,032)		$ 34,293		$ 461
Weighted-average shares, diluted (shares)	10,996		10,354		10,974		10,715
Diluted earnings/(loss) per common share (dollars per share)	$ 1.49		$ (2.22)		$ 3.12		$ 0.04

[1] For the three months ended September 30, 2012 and 2011, stock options and SARs of 296,873 and 1,294,066, 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 September 30, 2012 and 2011, contingent shares of non-vested restricted stock of 106,300 and 196,076, 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 nine months ended September 30, 2012 and 2011, stock options and SARs of 412,009 and 685,921, respectively, were outstanding but not included in the computation of diluted earnings per share of common stock because they were anti-dilutive. For the nine months ended September 30, 2012 and 2011, contingent shares of non-vested restricted stock of 97,300 and 150,353, respectively, were outstanding but not included in the computation of diluted earnings per share of common stock because performance conditions were not me