Stockholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended													12 Months Ended
	Dec. 31, 2016		Sep. 30, 2016	[2]	Jun. 30, 2016	[3]	Mar. 31, 2016	Dec. 31, 2015		Sep. 30, 2015	[5]	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 09, 2015	Dec. 04, 2013
Class of Stock [Line Items]
Common Stock, Shares Authorized	20,000,000							20,000,000						20,000,000	20,000,000
Common Stock, Shares, Issued	11,115,779							11,115,779						11,115,779	11,115,779
Common Stock, Par or Stated Value Per Share	$ 0.01							$ 0.01						$ 0.01	$ 0.01
Common Stock, Dividends, Per Share, Cash Paid	$ 0	[1]	$ 0.04		$ 0.04		$ 0.04	$ 0.04	[4]	$ 0.04		$ 0.04	$ 0.04	$ 0.12	$ 0.16	$ 0.13
Treasury Stock, Shares, Acquired														5,000	80,512
Treasury Stock, Value, Acquired, Cost Method														$ 67	$ 1,587
Payments for Repurchase of Common Stock														$ 342	$ 2,701	$ 985
Stock Repurchase Program Expiration Date														Dec. 31, 2017
Shares Paid for Tax Withholding for Share Based Compensation														20,186	25,340
Adjustments Related to Tax Withholding for Share-based Compensation														$ 275	$ 1,114
Dividends, Common Stock, Cash														$ 1,244	$ 1,656	$ 1,345
Common Stock [Member]
Class of Stock [Line Items]
Common Stock, Shares Authorized								20,000,000							20,000,000	20,000,000
Common Stock, Shares, Issued								11,115,779							11,115,779	11,115,779
Common Stock, Par or Stated Value Per Share								$ 0.01							$ 0.01
Treasury Stock, Shares, Acquired														5,000	80,512
Preferred Stock [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Authorized								5,000,000							5,000,000
Preferred Stock, Shares Issued	0							0						0	0
Preferred Stock, No Par Value	$ 0.00													$ 0.00
December 2013 Share Repurchase Program [Member]
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount																		$ 15,000
December 2015 Share Repurchase Program [Member]
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount																	$ 30,000

[1] Fourth quarter 2016 includes deferred U.S. income taxes and foreign withholding taxes of $7,932 on unremitted foreign earnings and a valuation allowance of $29,719 against deferred tax assets.

[2] Third quarter 2016 includes $6,946

[3] Second quarter 2016 includes $128,938 impairment of assets related to the Chemtec, Protective Coatings, IOS and Rail Technologies product groups.

[4] Fourth quarter 2015 includes $2,279 pre-tax gain on sale of Tucson, AZ concrete tie facility.

[5] Third quarter 2015 includes $80,337 impairment of goodwill related to the IOS and Chemtec reporting units.