Segments and Related Information (Schedule of Significant Customers, Revenue Concentration Information) (Details) - Customer Concentration Risk [Member] - Revenue [Member]		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Communications [Member] | AT&T [Member]
Revenue, Significant Customers [Line Items]
Significant customers, percentage of total consolidated revenue	[1],[2]	17.00%	25.00%	18.00%	24.00%
Communications [Member] | DIRECTV [Member]
Revenue, Significant Customers [Line Items]
Significant customers, percentage of total consolidated revenue	[1],[3]	12.00%	12.00%	13.00%	13.00%
Communications [Member] | AT&T and DIRECTV Combined [Member]
Revenue, Significant Customers [Line Items]
Significant customers, percentage of total consolidated revenue		30.00%	37.00%	31.00%	37.00%
Oil and Gas [Member] | Enbridge, Inc. [Member]
Revenue, Significant Customers [Line Items]
Significant customers, percentage of total consolidated revenue	[4]	1.00%	8.00%	1.00%	11.00%

[1] AT&T acquired DIRECTV® in July 2015. On a combined basis, AT&T and DIRECTV® represented 30% and 37% of consolidated revenue for the three month periods ended June 30, 2015 and 2014, respectively, and represented 31% and 37% for the six month periods ended June 30, 2015 and 2014.

[2] The Company’s relationship with AT&T is based upon master service agreements, other service agreements and construction/installation contracts for AT&T’s wireless, wireline/fiber and home security and automation businesses. Revenue from AT&T is included in the Communications segment.

[3] 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.

[4] 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.