Segments and Related Information (Schedule of Significant Customers, Revenue Concentration Information) (Details) - Customer Concentration Risk [Member] - Revenue [Member]		3 Months Ended
		Mar. 31, 2015	Mar. 31, 2014
AT&T [Member] | Communications [Member]
Revenue, Significant Customers [Line Items]
Significant customers, percentage of total consolidated revenue	[1],[2]	19.00%	22.00%
DIRECTV [Member] | Communications [Member]
Revenue, Significant Customers [Line Items]
Significant customers, percentage of total consolidated revenue	[1],[3]	14.00%	14.00%
Enbridge, Inc. [Member] | Oil and Gas [Member]
Revenue, Significant Customers [Line Items]
Significant customers, percentage of total consolidated revenue	[4]	1.00%	14.00%
AT&T and DIRECTV Combined [Member] | Communications [Member]
Revenue, Significant Customers [Line Items]
Significant customers, percentage of total consolidated revenue		32.00%	36.00%

[1] AT&T acquired DIRECTV® in July 2015. On a combined basis, AT&T and DIRECTV® represented 32% and 36% of consolidated revenue for the three month periods ended March 31, 2015 and 2014, respectively.

[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.