Acquisitions (Supplemental Noncash Investing Cash Flow Information) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended		0 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	May 01, 2013 Pipe and Foundation Group
Business Acquisition [Line Items]
Fair value of assets acquired			$ 188,930
Acquisition of business	(178,309)	0	(178,309)
Liabilities assumed			$ 10,621