Acquisitions (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended	0 Months Ended	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	May 01, 2013 Pipe and Foundation Group [Member] lb	Dec. 31, 2013 Pipe and Foundation Group [Member]
Business Acquisition [Line Items]
Business Combination, Annual Production Capacity				150,000,000
Cash paid for purchase	$ 178,309	$ 0	$ 0	$ 178,309
Business Combination, Acquisition Related Costs					$ 1,124

This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 25

-Paragraph 23

-URI http://asc.fasb.org/extlink&oid=21917927&loc=d3e1043-128460

Name:	us-gaap_BusinessCombinationAcquisitionRelatedCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration