Acquisitions (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Payments for Previous Acquisition	$ 495
L.B. Foster Ball Winch, Inc. [Member]
Business Acquisition [Line Items]
Business Acquisition, Name of Acquired Entity		Ball Winch, LLC (Ball Winch).
Payments to Acquire Businesses, Net of Cash Acquired		37,500
Business Combination, Indemnification Assets, Amount as of Acquisition Date		3,300
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net		37,995
Payments for Previous Acquisition	$ 495