Segments and Related Information (Schedule of Financial Information by Reportable Segment - EBITDA) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
EBITDA:
EBITDA	$ 151.0	$ 67.8	$ 292.6	$ 164.4
Reportable Segments [Member] | Communications [Member]
EBITDA:
EBITDA	62.8	49.7	190.9	141.8
Reportable Segments [Member] | Oil and Gas [Member]
EBITDA:
EBITDA	117.8	51.0	187.6	113.9
Reportable Segments [Member] | Electrical Transmission [Member]
EBITDA:
EBITDA	(8.3)	(23.7)	(42.0)	(47.6)
Reportable Segments [Member] | Power Generation and Industrial [Member]
EBITDA:
EBITDA	6.1	4.8	13.8	3.9
Reportable Segments [Member] | Other [Member]
EBITDA:
EBITDA	(3.1)	(2.0)	(2.6)	(7.1)
Corporate [Member]
EBITDA:
EBITDA	$ (24.3)	$ (12.0)	$ (55.1)	$ (40.5)