Accounting Policies - Earnings Per Share Anti-Dilutive (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net Income (Loss) Available to Common Stockholders, Basic		$ 10,317	$ 1,818
Net Income (Loss) Available to Common Stockholders, Diluted		$ 10,317	$ 1,818
Stock options, SARs and restricted stock	[1]	538,000	393,000
Weighted Average Number of Shares Outstanding, Basic		10,465,000	10,938,000
Basic earnings per common share		$ 0.99	$ 0.17
Earnings Per Share, On Incremental Common Shares Attributable to Share-based Payment Arrangements	[1]	$ (0.05)	$ (0.01)
Weighted Average Number of Shares Outstanding, Diluted		11,003,000	11,331,000
Diluted earnings per common share		$ 0.94000	$ 0.16000
Stock Options and SARs [Members]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share (shares)		210,865	201,401
Performance Shares [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share (shares)		37,284	30,514

[1] For the three months ended March 31, 2016 and 2015, stock options and SARs of 210,865 and 201,401, 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 March 31, 2016 and 2015, contingent shares of non-vested restricted stock of 37,284 and 30,514, respectively, were outstanding but not included in the computation of diluted earnings per share of common stock because performance conditions had not yet been met.