Business, Basis of Presentation and Significant Accounting Policies (Restatement of Previously Reported Condensed Unaudited Consolidated Financial Statements) (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue	$ 1,111,010	$ 1,315,488	$ 3,180,906	$ 3,380,538
Income tax expense	6,197	30,319	3,288	58,569
Net income from continuing operations	$ 7,442	$ 49,445	$ (2,766)	$ 95,447
Continuing operations, basic earnings per share (in dollars per share)	$ 0.10	$ 0.60	$ (0.03)	$ 1.21
Continuing operations, diluted earnings per share (in dollars per share)	0.09	0.57	(0.03)	1.11
Total basic earnings per share (in dollars per share)	0.10	0.60	(0.03)	1.20
Total diluted earnings per share (in dollars per share)	$ 0.09	$ 0.57	$ (0.03)	$ 1.10
Other current liabilities	$ 34,341		$ 34,341		$ 66,527
Costs and earnings in excess of billings	356,000		356,000		485,600
Billings in excess of costs and earnings	$ 123,623		$ 123,623		$ 155,674
Restatement Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Income tax expense		$ 2,300		$ 900
Net income from continuing operations		$ 3,700		$ 1,500
Continuing operations, basic earnings per share (in dollars per share)		$ 0.04		$ 0.02
Continuing operations, diluted earnings per share (in dollars per share)		0.04		0.02
Total basic earnings per share (in dollars per share)		0.05		0.02
Total diluted earnings per share (in dollars per share)		$ 0.04		$ 0.02
Billings in excess of costs and earnings		$ (1,300)		$ (1,300)
Current taxes payable		900		900
Restatement Adjustment [Member] | Contracts Accounted for under Percentage-of-Completion [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue		5,900		2,400
Costs and earnings in excess of billings		(4,200)		(4,200)
Restatement Adjustment [Member] | Contracts Accounted for under Percentage-of-Completion [Member] | Electrical Transmission [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Costs and earnings in excess of billings		1,100		1,100
Restatement Adjustment [Member] | Contracts Accounted for under Percentage-of-Completion [Member] | Reclassification Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Other current liabilities		(5,300)		(5,300)
Costs and earnings in excess of billings		$ (5,300)		$ (5,300)