Segments and Related Information (Schedule of Significant Customers, Revenue Concentration Information) (Details) - Customer Concentration Risk [Member] - Revenue [Member]		12 Months Ended
		Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
AT&T [Member] | Communications [Member]
Revenue, Significant Customer [Line Items]
Significant customers, percentage of total consolidated revenue	[1],[2]	21.00%	18.00%	18.00%
DIRECTV [Member] | Communications [Member]
Revenue, Significant Customer [Line Items]
Significant customers, percentage of total consolidated revenue	[1],[3]	12.00%	14.00%	17.00%
Enbridge, Inc. [Member] | Oil and Gas [Member]
Revenue, Significant Customer [Line Items]
Significant customers, percentage of total consolidated revenue	[4]	8.00%	18.00%	3.00%
AT&T and DIRECTV Combined [Member] | Communications [Member]
Revenue, Significant Customer [Line Items]
Significant customers, percentage of total consolidated revenue		33.00%	32.00%	34.00%

[1] AT&T acquired DIRECTV® in July 2015. On a combined basis, AT&T and DIRECTV® represented 33%, 32% and 34% of consolidated revenue for the years ended December 31, 2014, 2013 and 2012, 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.