Concentrations of Risk (Tables)

9 Months Ended

Sep. 30, 2013

Concentration Risk [Line Items]

Schedule of Major Customer Revenue Concentration

Revenue concentration information for significant customers, as a percent of total consolidated revenue from continuing operations, is as follows:

	For the Three Months Ended September 30,		For the Nine Months Ended September 30,
	2013	2012	2013	2012
Customer:
AT&T	16%	17%	18%	17%
DIRECTV®	13%	16%	15%	17%
Enbridge, Inc.	20%	3%	14%	1%

The Company's relationship with AT&T is based upon master service agreements, other service agreements and construction/installation contracts for both AT&T's wireless and wireline infrastructure businesses. Revenue from AT&T is included in the Communications segment.

The Company's relationship with DIRECTV® is based upon an agreement to provide installation and maintenance services for DIRECTV®. Revenue from DIRECTV® is included in the Communications segment.

The Company's relationship with Enbridge, Inc. is based upon various construction contracts for natural gas pipelines. Revenue from Enbridge, Inc. is included in the Oil and Gas segment.

Ten Largest Customers [Member]

Concentration Risk [Line Items]

Schedule of Major Customer Revenue Concentration

Revenue concentration information for the Company's top ten customers, as a percent of total consolidated revenue from continuing operations, is as follows:

	For the Three Months Ended September 30,		For the Nine Months Ended September 30,
	2013	2012	2013	2012
Revenue from top ten customers	73%	67%	69%	66%