Acquisitions (Allocation of Purchase Price) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Goodwill	$ 59,603	$ 57,781
L.B. Foster Ball Winch, Inc. [Member]
Business Acquisition [Line Items]
Current assets		1,857
Other assets		64
Property, plant and equipment		5,555
Goodwill		16,544
Other intangibles		14,682
Current liabilities		(707)
Total		37,995
Carr Concrete Corporation [Member]
Business Acquisition [Line Items]
Current assets	3,204
Other assets	145
Property, plant and equipment	7,648
Goodwill	1,822
Other intangibles	1,348
Current liabilities	(1,676)
Total	$ 12,491