Acquisitions (Identifiable Intangible Assets Acquired) (Details) (USD $) In Thousands, unless otherwise specified	0 Months Ended
	Dec. 30, 2014	Oct. 29, 2014	Jul. 07, 2014	Nov. 07, 2013
Chemtec [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets	$ 33,130
Chemtec [Member] | Trade name [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets	3,149
Chemtec [Member] | Customer relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets	23,934
Chemtec [Member] | Technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets	4,930
Chemtec [Member] | Non-compete agreements [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets	1,117
FWO [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets		419
FWO [Member] | Trade name [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets		0
FWO [Member] | Customer relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets		34
FWO [Member] | Technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets		341
FWO [Member] | Non-compete agreements [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets		44
Carr Concrete Corporation [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets			1,348
Carr Concrete Corporation [Member] | Trade name [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets			613
Carr Concrete Corporation [Member] | Customer relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets			524
Carr Concrete Corporation [Member] | Technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets			87
Carr Concrete Corporation [Member] | Non-compete agreements [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets			124
L.B. Foster Ball Winch, Inc. [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets				14,682
L.B. Foster Ball Winch, Inc. [Member] | Trade name [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets				723
L.B. Foster Ball Winch, Inc. [Member] | Customer relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets				0
L.B. Foster Ball Winch, Inc. [Member] | Technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets				11,129
L.B. Foster Ball Winch, Inc. [Member] | Non-compete agreements [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets				$ 2,830