Customer Concentrations (Tables)

12 Months Ended

Dec. 31, 2012

Description of Customer’s	2012				2011				2010
Business	Amount		Percentage		Amount		Percentage		Amount		Percentage
Texas DOT	$	88,783	5.8	%	$	*	*		$	*	*
Public gas and electric utility	224,845		14.6	%	165,373		11.3	%	69,212		7.3	%
Gas utility	86,786		5.6	%	*		*		*		*
Private gas and electric utility	106,804		6.9	%	*		*		*		*
Louisiana DOT	170,899		11.1	%	239,516		16.4	%	193,139		20.5	%
Public state agency	*		*		*		*		47,465		5.0	%
Gas utility (Ruby Pipeline Project)	12,553		0.8	%	274,898		18.8	%	79,224		8.4	%
	$	690,670	44.8	%	$	679,787	46.5	%	$	389,040	41.2	%

(*) Indicates a customer with less than 5% of revenues during such period.

Tabular disclosure of the nature of a concentration, a benchmark to which it is compared, and the percentage that the risk is to the benchmark.