Commitments and Contingencies (Details 2) (USD $)		0 Months Ended
	Nov. 30, 2011	Feb. 07, 2012 James Construction Group LLC North Texas Tollway Authority v. James Construction Group, LLC item	Mar. 31, 2013 Q3C	Nov. 30, 2012 Q3C	Sep. 30, 2013 Letters of credit	Dec. 31, 2012 Letters of credit	Sep. 30, 2013 Bonding	Dec. 31, 2012 Bonding
Commitments and contingencies
Total commercial letters of credit outstanding					$ 8,123,000	$ 6,168,000
Cost to repair retaining wall		5,400,000
Number of other walls constructed on the project, which could have potential exposure to failure		6
Bid and completion bonds issued and outstanding							1,449,158,000	1,298,589,000
Withdrawal liability recorded	$ 7,500,000		$ 119,000	$ 85,000