Segments and Related Information (Schedule of Segment Reporting Information, by Segment - Depreciation and Amortization) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Depreciation and amortization	$ 140,928	$ 92,601	$ 75,228
Continuing Operations [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization	140,926	91,958	74,151
Continuing Operations [Member] | Operating Segments [Member] | Communications [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization	36,800	29,100	24,500
Continuing Operations [Member] | Operating Segments [Member] | Oil and Gas [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization	80,900	42,000	30,700
Continuing Operations [Member] | Operating Segments [Member] | Electrical Transmission [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization	12,600	11,000	8,500
Continuing Operations [Member] | Operating Segments [Member] | Power Generation and Industrial [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization	6,700	6,700	7,700
Continuing Operations [Member] | Operating Segments [Member] | Other Segments [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization	0	100	100
Continuing Operations [Member] | Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization	$ 3,900	$ 3,100	$ 2,700