Segments and Related Information (Schedule of Significant Customers, Revenue Concentration Information) (Details) - Customer Concentration Risk [Member] - Revenue [Member]		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Communications [Member] | AT&T (including DIRECTV) [Member]
Revenue, Significant Customers [Line Items]
Significant customers, percentage of total consolidated revenue	[1],[2]	31.00%	28.00%	31.00%	33.00%
Oil and Gas [Member] | Enbridge, Inc. [Member]
Revenue, Significant Customers [Line Items]
Significant customers, percentage of total consolidated revenue	[3]	0.00%	10.00%	1.00%	10.00%

[1] DIRECTV® was acquired by AT&T in July 2015. Revenue from DIRECTV® is presented on a combined basis with AT&T for all periods.

[2] The Company’s relationship with AT&T is based upon multiple separate master service agreements, other service agreements and construction/installation contracts for AT&T’s (i) wireless, (ii) wireline/fiber, (iii) home security and automation businesses, and (iv) for DIRECTV® services, is based upon an agreement to provide installation and maintenance services. Revenue from AT&T is included in the Communications segment.

[3] 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.